diff --git a/typo3/sysext/backend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.ts b/typo3/sysext/backend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.tsconfig
similarity index 100%
rename from typo3/sysext/backend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.ts
rename to typo3/sysext/backend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.tsconfig
diff --git a/typo3/sysext/backend/ext_localconf.php b/typo3/sysext/backend/ext_localconf.php
index 5c9d69973f56ecf061208201599511713f77bc1d..c06b0372611fea5277fb7c11607a87791be12251 100644
--- a/typo3/sysext/backend/ext_localconf.php
+++ b/typo3/sysext/backend/ext_localconf.php
@@ -39,7 +39,7 @@ $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tsfebeuserauth.php'
 $GLOBALS['TYPO3_CONF_VARS']['SYS']['livesearch']['page'] = 'pages';
 
 // Include base TSconfig setup
-\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:backend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.ts">');
+\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig('<INCLUDE_TYPOSCRIPT: source="FILE:EXT:backend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.tsconfig">');
 
 // Register BackendLayoutDataProvider for PageTs
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['BackendLayoutDataProvider']['pagets'] = \TYPO3\CMS\Backend\Provider\PageTsBackendLayoutDataProvider::class;
diff --git a/typo3/sysext/belog/Classes/Controller/AbstractController.php b/typo3/sysext/belog/Classes/Controller/AbstractController.php
index a525dbe5dbfeb87a71eb1d8e55c6b696e06552d5..f4d7aa6120950b9acaf2115c4f369e875453f565 100644
--- a/typo3/sysext/belog/Classes/Controller/AbstractController.php
+++ b/typo3/sysext/belog/Classes/Controller/AbstractController.php
@@ -124,7 +124,7 @@ abstract class AbstractController extends ActionController
     {
         // @TODO: Extbase backend modules rely on frontend TypoScript for view, persistence
         // and settings. Thus, we need a TypoScript root template, that then loads the
-        // ext_typoscript_setup.txt file of this module. This is nasty, but can not be
+        // ext_typoscript_setup.typoscript file of this module. This is nasty, but can not be
         // circumvented until there is a better solution in extbase.
         // For now we throw an exception if no settings are detected.
         if (empty($this->settings)) {
diff --git a/typo3/sysext/belog/Configuration/TypoScript/setup.txt b/typo3/sysext/belog/Configuration/TypoScript/setup.typoscript
similarity index 100%
rename from typo3/sysext/belog/Configuration/TypoScript/setup.txt
rename to typo3/sysext/belog/Configuration/TypoScript/setup.typoscript
diff --git a/typo3/sysext/belog/ext_typoscript_setup.txt b/typo3/sysext/belog/ext_typoscript_setup.typoscript
similarity index 72%
rename from typo3/sysext/belog/ext_typoscript_setup.txt
rename to typo3/sysext/belog/ext_typoscript_setup.typoscript
index 037126ad237f081b51655781dc2ab28a54c7e968..3b0a45d2eab7924a80c8adfdf508fb36aa238684 100644
--- a/typo3/sysext/belog/ext_typoscript_setup.txt
+++ b/typo3/sysext/belog/ext_typoscript_setup.typoscript
@@ -1 +1 @@
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:belog/Configuration/TypoScript/setup.txt">
\ No newline at end of file
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:belog/Configuration/TypoScript/setup.typoscript">
diff --git a/typo3/sysext/beuser/Classes/Controller/BackendUserController.php b/typo3/sysext/beuser/Classes/Controller/BackendUserController.php
index b932f5179bc72e4d732a387028f4e22229877596..a2edc0d8aa7c0937c8b88b91bfa4eca7045495ec 100644
--- a/typo3/sysext/beuser/Classes/Controller/BackendUserController.php
+++ b/typo3/sysext/beuser/Classes/Controller/BackendUserController.php
@@ -117,7 +117,7 @@ class BackendUserController extends BackendUserActionController
     {
         // @TODO: Extbase backend modules relies on frontend TypoScript for view, persistence
         // and settings. Thus, we need a TypoScript root template, that then loads the
-        // ext_typoscript_setup.txt file of this module. This is nasty, but can not be
+        // ext_typoscript_setup.typoscript file of this module. This is nasty, but can not be
         // circumvented until there is a better solution in extbase.
         // For now we throw an exception if no settings are detected.
         if (empty($this->settings)) {
diff --git a/typo3/sysext/beuser/Classes/Controller/BackendUserGroupController.php b/typo3/sysext/beuser/Classes/Controller/BackendUserGroupController.php
index 4f1dc19cd000c4c525124dab4991f2801a6a70cd..00b3783d2ed20f2dc8878dfb5895c9f7b0fa67de 100644
--- a/typo3/sysext/beuser/Classes/Controller/BackendUserGroupController.php
+++ b/typo3/sysext/beuser/Classes/Controller/BackendUserGroupController.php
@@ -43,7 +43,7 @@ class BackendUserGroupController extends BackendUserActionController
     {
         // @TODO: Extbase backend modules relies on frontend TypoScript for view, persistence
         // and settings. Thus, we need a TypoScript root template, that then loads the
-        // ext_typoscript_setup.txt file of this module. This is nasty, but can not be
+        // ext_typoscript_setup.typoscript file of this module. This is nasty, but can not be
         // circumvented until there is a better solution in extbase.
         // For now we throw an exception if no settings are detected.
         if (empty($this->settings)) {
diff --git a/typo3/sysext/beuser/Configuration/TypoScript/setup.txt b/typo3/sysext/beuser/Configuration/TypoScript/setup.typoscript
similarity index 100%
rename from typo3/sysext/beuser/Configuration/TypoScript/setup.txt
rename to typo3/sysext/beuser/Configuration/TypoScript/setup.typoscript
diff --git a/typo3/sysext/beuser/ext_typoscript_setup.txt b/typo3/sysext/beuser/ext_typoscript_setup.typoscript
similarity index 71%
rename from typo3/sysext/beuser/ext_typoscript_setup.txt
rename to typo3/sysext/beuser/ext_typoscript_setup.typoscript
index f07dc5d24917f56dbf6b172c8518c0178f97e67f..78688e791774f037889e7c7aa56404e719658187 100644
--- a/typo3/sysext/beuser/ext_typoscript_setup.txt
+++ b/typo3/sysext/beuser/ext_typoscript_setup.typoscript
@@ -1 +1 @@
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:beuser/Configuration/TypoScript/setup.txt">
\ No newline at end of file
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:beuser/Configuration/TypoScript/setup.typoscript">
diff --git a/typo3/sysext/core/Classes/TypoScript/Parser/TypoScriptParser.php b/typo3/sysext/core/Classes/TypoScript/Parser/TypoScriptParser.php
index 5ae037067cf95d931ac4f6aef80205585038bfa1..e276d3fc675fb8f7d8074bcd48662c5497137032 100644
--- a/typo3/sysext/core/Classes/TypoScript/Parser/TypoScriptParser.php
+++ b/typo3/sysext/core/Classes/TypoScript/Parser/TypoScriptParser.php
@@ -885,7 +885,7 @@ class TypoScriptParser
 
                 // load default TypoScript for content rendering templates like
                 // fluid_styled_content if those have been included through f.e.
-                // <INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/setup.txt">
+                // <INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/setup.typoscript">
                 if (strpos(strtolower($filename), 'ext:') === 0) {
                     $filePointerPathParts = explode('/', substr($filename, 4));
 
@@ -1079,19 +1079,36 @@ class TypoScriptParser
             // Check for allowed files
             if (!GeneralUtility::verifyFilenameAgainstDenyPattern($absfilename)) {
                 $newString .= self::typoscriptIncludeError('File "' . $filename . '" was not included since it is not allowed due to fileDenyPattern.');
-            } elseif (!@file_exists($absfilename)) {
-                $newString .= self::typoscriptIncludeError('File "' . $filename . '" was not found.');
             } else {
-                $includedFiles[] = $absfilename;
-                // check for includes in included text
-                $included_text = self::checkIncludeLines(file_get_contents($absfilename), $cycle_counter + 1, $returnFiles, $absfilename);
-                // If the method also has to return all included files, merge currently included
-                // files with files included by recursively calling itself
-                if ($returnFiles && is_array($included_text)) {
-                    $includedFiles = array_merge($includedFiles, $included_text['files']);
-                    $included_text = $included_text['typoscript'];
+                $fileExists = false;
+                if (@file_exists($absfilename)) {
+                    $fileExists = true;
+                } else {
+                    // BC layer after renaming core TypoScript files from .txt to .typoscript
+                    if (substr($absfilename, -4, 4) === '.txt') {
+                        $absfilename = substr($absfilename, 0, -4) . '.typoscript';
+                        if (@file_exists($absfilename)) {
+                            trigger_error('The TypoScript file ' . $filename . ' was renamed to .typoscript extension.'
+                                . ' Update your "<INCLUDE_TYPOSCRIPT" statements.', E_USER_DEPRECATED);
+                            $fileExists = true;
+                        }
+                    }
+                }
+
+                if ($fileExists) {
+                    $includedFiles[] = $absfilename;
+                    // check for includes in included text
+                    $included_text = self::checkIncludeLines(file_get_contents($absfilename), $cycle_counter + 1, $returnFiles, $absfilename);
+                    // If the method also has to return all included files, merge currently included
+                    // files with files included by recursively calling itself
+                    if ($returnFiles && is_array($included_text)) {
+                        $includedFiles = array_merge($includedFiles, $included_text['files']);
+                        $included_text = $included_text['typoscript'];
+                    }
+                    $newString .= $included_text . LF;
+                } else {
+                    $newString .= self::typoscriptIncludeError('File "' . $filename . '" was not found.');
                 }
-                $newString .= $included_text . LF;
             }
         }
         $newString .= '### <INCLUDE_TYPOSCRIPT: source="FILE:' . $filename . '"' . $optionalProperties . '> END:' . LF . LF;
diff --git a/typo3/sysext/core/Documentation/Changelog/master/Deprecation-81686-AccessingCoreTypoScriptWithTxtFileExtensionHasBeenDeprecated.rst b/typo3/sysext/core/Documentation/Changelog/master/Deprecation-81686-AccessingCoreTypoScriptWithTxtFileExtensionHasBeenDeprecated.rst
new file mode 100644
index 0000000000000000000000000000000000000000..f602c40b21f405a0c02f627f7df9a1578e9b2a31
--- /dev/null
+++ b/typo3/sysext/core/Documentation/Changelog/master/Deprecation-81686-AccessingCoreTypoScriptWithTxtFileExtensionHasBeenDeprecated.rst
@@ -0,0 +1,42 @@
+.. include:: ../../Includes.txt
+
+============================================================================================
+Deprecation: #81686 - Accessing core TypoScript with .txt file extension has been deprecated
+============================================================================================
+
+See :issue:`81686`
+
+Description
+===========
+
+TYPO3 Core TypoScript files were renamed from :file:`.txt` extension to :file:`.typoscript` and :file:`.tsconfig`.
+The backward compatibility layer has been introduced for :typoscript:`<INCLUDE_TYPOSCRIPT` inclusion.
+If including file with :file:`.txt` does not exists, then TYPO3 will try to load a file with :file:`.typoscript` extension.
+
+
+Impact
+======
+
+Installations including Core TypoScript using old file extension will report a deprecation notice.
+
+
+Migration
+=========
+
+Rename file name from :file:`.txt` to :file:`.typoscript` extension.
+For example code like:
+
+.. code-block:: typoscript
+
+   <INCLUDE_TYPOSCRIPT: source="FILE:EXT:form/Configuration/TypoScript/setup.txt">
+   <INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/constants.txt">
+
+should be changed to:
+
+.. code-block:: typoscript
+
+   <INCLUDE_TYPOSCRIPT: source="FILE:EXT:form/Configuration/TypoScript/setup.typoscript">
+   <INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/constants.typoscript">
+
+
+.. index:: TSConfig, TypoScript, NotScanned
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/FAL/AbstractActionTestCase.php b/typo3/sysext/core/Tests/Functional/DataHandling/FAL/AbstractActionTestCase.php
index 3152cfc7da685a25d9d3af2941bab4b0effea726..4cef5b282378e4c466d86a294e2f84d5db745f60 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/FAL/AbstractActionTestCase.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/FAL/AbstractActionTestCase.php
@@ -54,7 +54,7 @@ abstract class AbstractActionTestCase extends \TYPO3\CMS\Core\Tests\Functional\D
         $this->importScenarioDataSet('LiveDefaultElements');
         $this->importDataSet('PACKAGE:typo3/testing-framework/Resources/Core/Functional/Fixtures/sys_file_storage.xml');
 
-        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts']);
+        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript']);
         $this->backendUser->workspace = 0;
     }
 
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/FAL/Modify/ActionTest.php b/typo3/sysext/core/Tests/Functional/DataHandling/FAL/Modify/ActionTest.php
index 20846c352f8740b4537b5ee4c4ac4200da8119a7..db8256be6c61537b2846c2bb24b5adeedef85277 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/FAL/Modify/ActionTest.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/FAL/Modify/ActionTest.php
@@ -88,8 +88,8 @@ class ActionTest extends \TYPO3\CMS\Core\Tests\Functional\DataHandling\FAL\Abstr
         $this->assertAssertionDataSet('copyContentToLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageId)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/Group/AbstractActionTestCase.php b/typo3/sysext/core/Tests/Functional/DataHandling/Group/AbstractActionTestCase.php
index af39992c6e6dd447fc378e0bd2a984b0b5d74542..4ac52e01b0a11ec370d413987c1463775ce592cb 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/Group/AbstractActionTestCase.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/Group/AbstractActionTestCase.php
@@ -48,7 +48,7 @@ abstract class AbstractActionTestCase extends \TYPO3\CMS\Core\Tests\Functional\D
         $this->importScenarioDataSet('LiveDefaultElements');
         $this->importScenarioDataSet('ReferenceIndex');
 
-        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts']);
+        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript']);
     }
 
     /**
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/Group/Modify/ActionTest.php b/typo3/sysext/core/Tests/Functional/DataHandling/Group/Modify/ActionTest.php
index 12bfc7fa0215a9db0e12710ca6c68da007a14774..88ee453ff8c99117eddd37bbaf6f750fabe717b8 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/Group/Modify/ActionTest.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/Group/Modify/ActionTest.php
@@ -245,8 +245,8 @@ class ActionTest extends \TYPO3\CMS\Core\Tests\Functional\DataHandling\Group\Abs
         $this->assertAssertionDataSet('copyContentToLanguageOfRelation');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageId)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionStructureHasRecordConstraint()
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/CSV/AbstractActionTestCase.php b/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/CSV/AbstractActionTestCase.php
index 61be40090d4d6b06c5e5bd9e963e5f8fa8cd03b3..796ba82276b0f82cc1809ca0c06e018febdadf9f 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/CSV/AbstractActionTestCase.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/CSV/AbstractActionTestCase.php
@@ -48,7 +48,7 @@ abstract class AbstractActionTestCase extends \TYPO3\CMS\Core\Tests\Functional\D
         $this->importScenarioDataSet('LiveDefaultPages');
         $this->importScenarioDataSet('LiveDefaultElements');
 
-        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts']);
+        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript']);
         $this->backendUser->workspace = 0;
     }
 
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/CSV/Modify/ActionTest.php b/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/CSV/Modify/ActionTest.php
index 7b74765ce2c83594ab9f07c8bae8f428afd4e5ec..143f4d76068d6532989fccdbd9f906800448a52f 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/CSV/Modify/ActionTest.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/CSV/Modify/ActionTest.php
@@ -113,8 +113,8 @@ class ActionTest extends \TYPO3\CMS\Core\Tests\Functional\DataHandling\IRRE\CSV\
         $this->assertAssertionDataSet('copyParentContentToLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageId)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionStructureHasRecordConstraint()
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/ForeignField/AbstractActionTestCase.php b/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/ForeignField/AbstractActionTestCase.php
index 9c26360ffc9e4ac2b366d89a55bcf20f9758a7fa..57b32e0cb2d6e811f228e151a343b54481c06c78 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/ForeignField/AbstractActionTestCase.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/ForeignField/AbstractActionTestCase.php
@@ -58,8 +58,8 @@ abstract class AbstractActionTestCase extends \TYPO3\CMS\Core\Tests\Functional\D
         $this->setUpFrontendRootPage(
             1,
             [
-                'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-                'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.ts',
+                'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+                'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.typoscript',
             ]
         );
         $this->backendUser->workspace = 0;
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/ForeignField/Modify/ActionTest.php b/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/ForeignField/Modify/ActionTest.php
index 8e1ab4e53d71922ce91237c6fb50cae47d5f29b5..46d0db5a18990f2737f8a883a79b9a2df435c1c2 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/ForeignField/Modify/ActionTest.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/IRRE/ForeignField/Modify/ActionTest.php
@@ -113,9 +113,9 @@ class ActionTest extends \TYPO3\CMS\Core\Tests\Functional\DataHandling\IRRE\Fore
         $this->assertAssertionDataSet('copyParentContentToLanguageWAllChildren');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageId)->getResponseSections('Default', 'Extbase:list()');
         $this->assertThat($responseSections, $this->getRequestSectionStructureHasRecordConstraint()
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/ManyToMany/AbstractActionTestCase.php b/typo3/sysext/core/Tests/Functional/DataHandling/ManyToMany/AbstractActionTestCase.php
index 74b685178423d071e0f0970a46d08492374cbec1..e6c243f13a17f2d6508bfa48a72dc7948f3b4e0b 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/ManyToMany/AbstractActionTestCase.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/ManyToMany/AbstractActionTestCase.php
@@ -48,7 +48,7 @@ abstract class AbstractActionTestCase extends \TYPO3\CMS\Core\Tests\Functional\D
         $this->importScenarioDataSet('LiveDefaultPages');
         $this->importScenarioDataSet('LiveDefaultElements');
 
-        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts']);
+        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript']);
         $this->backendUser->workspace = 0;
     }
 
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/Regular/AbstractActionTestCase.php b/typo3/sysext/core/Tests/Functional/DataHandling/Regular/AbstractActionTestCase.php
index 613086af702f108a45b355537a19b33f1b4b60f3..a43f280e698867e93194a0d12f10db879f935b70 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/Regular/AbstractActionTestCase.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/Regular/AbstractActionTestCase.php
@@ -45,7 +45,7 @@ abstract class AbstractActionTestCase extends \TYPO3\CMS\Core\Tests\Functional\D
         $this->importScenarioDataSet('LiveDefaultPages');
         $this->importScenarioDataSet('LiveDefaultElements');
 
-        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts']);
+        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript']);
         $this->backendUser->workspace = 0;
     }
 
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/Regular/Modify/ActionTest.php b/typo3/sysext/core/Tests/Functional/DataHandling/Regular/Modify/ActionTest.php
index 32cd9b13b4c9c6d4a5a52ce78864e64daf171317..86cddca076c11651c7dff24287f325de0759fb11 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/Regular/Modify/ActionTest.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/Regular/Modify/ActionTest.php
@@ -125,8 +125,8 @@ class ActionTest extends \TYPO3\CMS\Core\Tests\Functional\DataHandling\Regular\A
         $this->assertAssertionDataSet('copyContentToLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageId)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()
@@ -143,8 +143,8 @@ class ActionTest extends \TYPO3\CMS\Core\Tests\Functional\DataHandling\Regular\A
         $this->assertAssertionDataSet('copyContentToLanguageFromNonDefaultLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageIdSecond)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()
diff --git a/typo3/sysext/core/Tests/Functional/DataHandling/Select/AbstractActionTestCase.php b/typo3/sysext/core/Tests/Functional/DataHandling/Select/AbstractActionTestCase.php
index c06a07235129ee42b4112fcd07e63b57fa846b04..033f05835bfafcf68b7d310dcf15427f9b1dfc30 100644
--- a/typo3/sysext/core/Tests/Functional/DataHandling/Select/AbstractActionTestCase.php
+++ b/typo3/sysext/core/Tests/Functional/DataHandling/Select/AbstractActionTestCase.php
@@ -47,7 +47,7 @@ abstract class AbstractActionTestCase extends \TYPO3\CMS\Core\Tests\Functional\D
         $this->importScenarioDataSet('LiveDefaultElements');
         $this->importScenarioDataSet('ReferenceIndex');
 
-        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts']);
+        $this->setUpFrontendRootPage(1, ['typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript']);
     }
 
     /**
diff --git a/typo3/sysext/core/Tests/Functional/Fixtures/Extensions/irre_tutorial/Configuration/TypoScript/constants.txt b/typo3/sysext/core/Tests/Functional/Fixtures/Extensions/irre_tutorial/Configuration/TypoScript/constants.typoscript
similarity index 100%
rename from typo3/sysext/core/Tests/Functional/Fixtures/Extensions/irre_tutorial/Configuration/TypoScript/constants.txt
rename to typo3/sysext/core/Tests/Functional/Fixtures/Extensions/irre_tutorial/Configuration/TypoScript/constants.typoscript
diff --git a/typo3/sysext/core/Tests/Functional/Fixtures/Extensions/irre_tutorial/Configuration/TypoScript/setup.txt b/typo3/sysext/core/Tests/Functional/Fixtures/Extensions/irre_tutorial/Configuration/TypoScript/setup.typoscript
similarity index 100%
rename from typo3/sysext/core/Tests/Functional/Fixtures/Extensions/irre_tutorial/Configuration/TypoScript/setup.txt
rename to typo3/sysext/core/Tests/Functional/Fixtures/Extensions/irre_tutorial/Configuration/TypoScript/setup.typoscript
diff --git a/typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.ts b/typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.typoscript
similarity index 92%
rename from typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.ts
rename to typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.typoscript
index fb774f41ea136af0078025583e5cf8391aa81390..22a01a87811dcb71ce2e91bd19b9a50f3ada5fe7 100644
--- a/typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.ts
+++ b/typo3/sysext/core/Tests/Functional/Fixtures/Frontend/ExtbaseJsonRenderer.typoscript
@@ -1,4 +1,4 @@
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:irre_tutorial/Configuration/TypoScript/setup.txt">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:irre_tutorial/Configuration/TypoScript/setup.typoscript">
 
 page {
 	20 = COA
diff --git a/typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts b/typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript
similarity index 100%
rename from typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts
rename to typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript
diff --git a/typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts b/typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript
similarity index 100%
rename from typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts
rename to typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript
diff --git a/typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/DefaultStyles/setup.txt b/typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/DefaultStyles/setup.typoscript
similarity index 100%
rename from typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/DefaultStyles/setup.txt
rename to typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/DefaultStyles/setup.typoscript
diff --git a/typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/constants.txt b/typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/constants.typoscript
similarity index 100%
rename from typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/constants.txt
rename to typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/constants.typoscript
diff --git a/typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/setup.txt b/typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/setup.typoscript
similarity index 100%
rename from typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/setup.txt
rename to typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/setup.typoscript
diff --git a/typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/ext_typoscript_setup.txt b/typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/ext_typoscript_setup.typoscript
similarity index 100%
rename from typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/ext_typoscript_setup.txt
rename to typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/ext_typoscript_setup.typoscript
diff --git a/typo3/sysext/extbase/Tests/Functional/Persistence/EnableFieldsTest.php b/typo3/sysext/extbase/Tests/Functional/Persistence/EnableFieldsTest.php
index fbf7ea76aca2e1bded489effd9f55745f6c47198..6158933d363360e0c35de49d1676ca68a54ba6d2 100644
--- a/typo3/sysext/extbase/Tests/Functional/Persistence/EnableFieldsTest.php
+++ b/typo3/sysext/extbase/Tests/Functional/Persistence/EnableFieldsTest.php
@@ -45,7 +45,7 @@ class EnableFieldsTest extends AbstractDataHandlerActionTestCase
         $this->importDataSet(ORIGINAL_ROOT . 'typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/fe_users.xml');
         $this->importDataSet(ORIGINAL_ROOT . 'typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/blogs-with-fe_groups.xml');
 
-        $this->setUpFrontendRootPage(1, ['typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/JsonRenderer.ts']);
+        $this->setUpFrontendRootPage(1, ['typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/JsonRenderer.typoscript']);
     }
 
     /**
diff --git a/typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/ContentJsonRenderer.ts b/typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/ContentJsonRenderer.typoscript
similarity index 100%
rename from typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/ContentJsonRenderer.ts
rename to typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/ContentJsonRenderer.typoscript
diff --git a/typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/JsonRenderer.ts b/typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/JsonRenderer.typoscript
similarity index 100%
rename from typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/JsonRenderer.ts
rename to typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/JsonRenderer.typoscript
diff --git a/typo3/sysext/extbase/Tests/Functional/Persistence/TranslatedContentTest.php b/typo3/sysext/extbase/Tests/Functional/Persistence/TranslatedContentTest.php
index 6eb1eee4fe2be872947f7c9ffde770cfc8891919..79714c7b1971ba6588e54bc6e745cbc954edd078 100644
--- a/typo3/sysext/extbase/Tests/Functional/Persistence/TranslatedContentTest.php
+++ b/typo3/sysext/extbase/Tests/Functional/Persistence/TranslatedContentTest.php
@@ -86,8 +86,8 @@ class TranslatedContentTest extends \TYPO3\CMS\Core\Tests\Functional\DataHandlin
         $this->objectManager = GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\Object\ObjectManager::class);
         $this->contentRepository = $this->objectManager->get(\ExtbaseTeam\BlogExample\Domain\Repository\TtContentRepository::class);
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/setup.txt',
-            'typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/ContentJsonRenderer.ts'
+            'typo3/sysext/extbase/Tests/Functional/Fixtures/Extensions/blog_example/Configuration/TypoScript/setup.typoscript',
+            'typo3/sysext/extbase/Tests/Functional/Persistence/Fixtures/Frontend/ContentJsonRenderer.typoscript'
 
         ]);
     }
diff --git a/typo3/sysext/extbase/ext_typoscript_setup.txt b/typo3/sysext/extbase/ext_typoscript_setup.typoscript
similarity index 100%
rename from typo3/sysext/extbase/ext_typoscript_setup.txt
rename to typo3/sysext/extbase/ext_typoscript_setup.typoscript
diff --git a/typo3/sysext/extensionmanager/ext_typoscript_setup.txt b/typo3/sysext/extensionmanager/ext_typoscript_setup.typoscript
similarity index 100%
rename from typo3/sysext/extensionmanager/ext_typoscript_setup.txt
rename to typo3/sysext/extensionmanager/ext_typoscript_setup.typoscript
diff --git a/typo3/sysext/fluid/ext_typoscript_setup.txt b/typo3/sysext/fluid/ext_typoscript_setup.typoscript
similarity index 100%
rename from typo3/sysext/fluid/ext_typoscript_setup.txt
rename to typo3/sysext/fluid/ext_typoscript_setup.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Bullets.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Bullets.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Bullets.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Bullets.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Div.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Div.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Div.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Div.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Header.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Header.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Header.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Header.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Html.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Html.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Html.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Html.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Image.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Image.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Image.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Image.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/List.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/List.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/List.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/List.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuAbstract.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuAbstract.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuAbstract.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuAbstract.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedContent.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedContent.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedContent.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedContent.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedPages.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedPages.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedPages.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedPages.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuPages.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuPages.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuPages.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuPages.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRecentlyUpdated.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRecentlyUpdated.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRecentlyUpdated.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRecentlyUpdated.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRelatedPages.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRelatedPages.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRelatedPages.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRelatedPages.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSection.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSection.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSection.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSection.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSectionPages.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSectionPages.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSectionPages.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSectionPages.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemap.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemap.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemap.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemap.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemapPages.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemapPages.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemapPages.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemapPages.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSubpages.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSubpages.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSubpages.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSubpages.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Shortcut.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Shortcut.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Shortcut.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Shortcut.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Table.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Table.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Table.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Table.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Text.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Text.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Text.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Text.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Textmedia.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Textmedia.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Textmedia.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Textmedia.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Textpic.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Textpic.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Textpic.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Textpic.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Uploads.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Uploads.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Uploads.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/ContentElement/Uploads.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/Helper/ContentElement.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/Helper/ContentElement.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/Helper/ContentElement.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/Helper/ContentElement.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/Helper/ParseFunc.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/Helper/ParseFunc.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/Helper/ParseFunc.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/Helper/ParseFunc.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/Styling/setup.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/Styling/setup.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/Styling/setup.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/Styling/setup.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/constants.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/constants.typoscript
similarity index 100%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/constants.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/constants.typoscript
diff --git a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/setup.txt b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/setup.typoscript
similarity index 57%
rename from typo3/sysext/fluid_styled_content/Configuration/TypoScript/setup.txt
rename to typo3/sysext/fluid_styled_content/Configuration/TypoScript/setup.typoscript
index 1ccbd612a547a5ee350ea3b140a93cf8ef79a4ab..db6d335c205ad4b746839917fe293053c4fd5dc9 100644
--- a/typo3/sysext/fluid_styled_content/Configuration/TypoScript/setup.txt
+++ b/typo3/sysext/fluid_styled_content/Configuration/TypoScript/setup.typoscript
@@ -1,6 +1,6 @@
 # Include setup
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/Helper/ContentElement.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/Helper/ParseFunc.txt">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/Helper/ContentElement.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/Helper/ParseFunc.typoscript">
 
 
 # Content element rendering
@@ -20,29 +20,29 @@ tt_content {
 
 
 # Typical content elements
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Bullets.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Div.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Header.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Html.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Image.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/List.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Shortcut.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Table.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Text.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Textmedia.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Textpic.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Uploads.txt">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Bullets.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Div.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Header.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Html.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Image.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/List.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Shortcut.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Table.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Text.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Textmedia.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Textpic.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/Uploads.typoscript">
 
 
 # Menu content elements
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuAbstract.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedContent.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedPages.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuPages.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSubpages.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSection.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSectionPages.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRecentlyUpdated.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRelatedPages.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemap.txt">
-<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemapPages.txt">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuAbstract.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedContent.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuCategorizedPages.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuPages.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSubpages.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSection.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSectionPages.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRecentlyUpdated.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuRelatedPages.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemap.typoscript">
+<INCLUDE_TYPOSCRIPT: source="FILE:EXT:fluid_styled_content/Configuration/TypoScript/ContentElement/MenuSitemapPages.typoscript">
diff --git a/typo3/sysext/fluid_styled_content/Documentation/Configuration/OverridingFluidTemplates/Index.rst b/typo3/sysext/fluid_styled_content/Documentation/Configuration/OverridingFluidTemplates/Index.rst
index bcba0df22af1a684f32e4f49b92ab864a0c63b86..6ee60d7b1acb99343725c2c7f8528f561aaa54e0 100644
--- a/typo3/sysext/fluid_styled_content/Documentation/Configuration/OverridingFluidTemplates/Index.rst
+++ b/typo3/sysext/fluid_styled_content/Documentation/Configuration/OverridingFluidTemplates/Index.rst
@@ -8,7 +8,7 @@ Overriding the FLUID templates
 
 At :ref:`typoscript` we have described the way content elements are rendered.
 
-By default these settings are done in the file :file:`setup.txt` which can be found in the
+By default these settings are done in the file :file:`setup.typoscript` which can be found in the
 folder :file:`EXT:fluid_styled_content/Configuration/TypoScript/`.
 
 
@@ -34,7 +34,7 @@ the same as `partialRootPaths` and `layoutRootPaths`:
       }
    }
 
-A content element is using a `templateName`, which is defined in :file:`setup.txt`. You
+A content element is using a `templateName`, which is defined in :file:`setup.typoscript`. You
 can override this value, but the template from the extension "fluid_styled_content" will
 not be loaded then, since its name is still the default value.
 
diff --git a/typo3/sysext/fluid_styled_content/Documentation/Configuration/TypoScript/Index.rst b/typo3/sysext/fluid_styled_content/Documentation/Configuration/TypoScript/Index.rst
index 3a692d6f0efd72218d103e82033bfca5fc5c05b3..8cf7737a768f4eba3ea6671650d72a6975669ba3 100644
--- a/typo3/sysext/fluid_styled_content/Documentation/Configuration/TypoScript/Index.rst
+++ b/typo3/sysext/fluid_styled_content/Documentation/Configuration/TypoScript/Index.rst
@@ -17,61 +17,61 @@ in the directory :file:`EXT:fluid_styled_content/Configuration/TypoScript/`.
 
 In this folder there are two files:
 
-- :file:`constants.txt` - The file with the default constants. The "Constant Editor", as
+- :file:`constants.typoscript` - The file with the default constants. The "Constant Editor", as
   described above, is using this file for its default settings.
 
-- :file:`setup.txt` - This file will first include some other files which are located in
+- :file:`setup.typoscript` - This file will first include some other files which are located in
   the "Setup" folder in the same directory. More about these files later.
 
 In the folder :file:`ContentElement` there are files which are included by the file
-:file:`setup.txt` as mentioned above. These files contain the rendering definitions of all
+:file:`setup.typoscript` as mentioned above. These files contain the rendering definitions of all
 content elements, that are provided by the TYPO3 core. These are:
 
-- :file:`Bullets.txt` - Configuration for Content Element "Bullet List"
+- :file:`Bullets.typoscript` - Configuration for Content Element "Bullet List"
 
-- :file:`Div.txt` - Configuration for Content Element "Divider"
+- :file:`Div.typoscript` - Configuration for Content Element "Divider"
 
-- :file:`Header.txt` - Configuration for Content Element "Header Only"
+- :file:`Header.typoscript` - Configuration for Content Element "Header Only"
 
-- :file:`Html.txt` - Configuration for Content Element "Plain HTML"
+- :file:`Html.typoscript` - Configuration for Content Element "Plain HTML"
 
-- :file:`Image.txt` - Configuration for Content Element "Image"
+- :file:`Image.typoscript` - Configuration for Content Element "Image"
 
-- :file:`List.txt` - Configuration for Content Element "General Plugin"
+- :file:`List.typoscript` - Configuration for Content Element "General Plugin"
 
-- :file:`MenuAbstract.txt` - Configuration for Content Element "Menu of subpages of selected pages including abstracts"
+- :file:`MenuAbstract.typoscript` - Configuration for Content Element "Menu of subpages of selected pages including abstracts"
 
-- :file:`MenuCategorizedContent.txt` - Configuration for Content Element "Content elements for selected categories"
+- :file:`MenuCategorizedContent.typoscript` - Configuration for Content Element "Content elements for selected categories"
 
-- :file:`MenuCategorizedPages.txt` - Configuration for Content Element "Pages for selected categories"
+- :file:`MenuCategorizedPages.typoscript` - Configuration for Content Element "Pages for selected categories"
 
-- :file:`MenuPages.txt` - Configuration for Content Element "Menu of selected pages"
+- :file:`MenuPages.typoscript` - Configuration for Content Element "Menu of selected pages"
 
-- :file:`MenuRecentlyUpdated.txt` - Configuration for Content Element "Recently updated pages"
+- :file:`MenuRecentlyUpdated.typoscript` - Configuration for Content Element "Recently updated pages"
 
-- :file:`MenuRelatedPages.txt` - Configuration for Content Element "Related pages (based on keywords)"
+- :file:`MenuRelatedPages.typoscript` - Configuration for Content Element "Related pages (based on keywords)"
 
-- :file:`MenuSection.txt` - Configuration for Content Element "Section index (page content marked for section menus)"
+- :file:`MenuSection.typoscript` - Configuration for Content Element "Section index (page content marked for section menus)"
 
-- :file:`MenuSectionPages.txt` - Configuration for Content Element "Menu of subpages of selected pages including sections"
+- :file:`MenuSectionPages.typoscript` - Configuration for Content Element "Menu of subpages of selected pages including sections"
 
-- :file:`MenuSitemap.txt` - Configuration for Content Element "Sitemap"
+- :file:`MenuSitemap.typoscript` - Configuration for Content Element "Sitemap"
 
-- :file:`MenuSitemapPages.txt` - Configuration for Content Element "Sitemaps of selected pages"
+- :file:`MenuSitemapPages.typoscript` - Configuration for Content Element "Sitemaps of selected pages"
 
-- :file:`MenuSubpages.txt` - Configuration for Content Element "Menu of subpages of selected pages"
+- :file:`MenuSubpages.typoscript` - Configuration for Content Element "Menu of subpages of selected pages"
 
-- :file:`Shortcut.txt` - Configuration for Content Element "Insert records"
+- :file:`Shortcut.typoscript` - Configuration for Content Element "Insert records"
 
-- :file:`Table.txt` - Configuration for Content Element "Table"
+- :file:`Table.typoscript` - Configuration for Content Element "Table"
 
-- :file:`Text.txt` - Configuration for Content Element "Regular Text Element"
+- :file:`Text.typoscript` - Configuration for Content Element "Regular Text Element"
 
-- :file:`Textmedia.txt` - Configuration for Content Element "Text and Media"
+- :file:`Textmedia.typoscript` - Configuration for Content Element "Text and Media"
 
-- :file:`Textpic.txt` - Configuration for Content Element "Text and Images"
+- :file:`Textpic.typoscript` - Configuration for Content Element "Text and Images"
 
-- :file:`Uploads.txt` - Configuration for Content Element "File Links"
+- :file:`Uploads.typoscript` - Configuration for Content Element "File Links"
 
 Since we move away from TypoScript as much as possible, these rendering
 definitions only declare the following:
@@ -87,9 +87,9 @@ definitions only declare the following:
   see this in action.
 
 In the folder :file:`Helper` there are files which are included by the file
-:file:`setup.txt` as mentioned above. These are:
+:file:`setup.typoscript` as mentioned above. These are:
 
-- :file:`ContentElement.txt` - Default configuration for content elements using
+- :file:`ContentElement.typoscript` - Default configuration for content elements using
   FLUIDTEMPLATE
 
-- :file:`ParseFunc.txt` - Creates persistent ParseFunc setup for non-HTML content
+- :file:`ParseFunc.typoscript` - Creates persistent ParseFunc setup for non-HTML content
diff --git a/typo3/sysext/form/Configuration/PageTS/modWizards.ts b/typo3/sysext/form/Configuration/PageTS/modWizards.tsconfig
similarity index 100%
rename from typo3/sysext/form/Configuration/PageTS/modWizards.ts
rename to typo3/sysext/form/Configuration/PageTS/modWizards.tsconfig
diff --git a/typo3/sysext/form/Configuration/TypoScript/setup.txt b/typo3/sysext/form/Configuration/TypoScript/setup.typoscript
similarity index 100%
rename from typo3/sysext/form/Configuration/TypoScript/setup.txt
rename to typo3/sysext/form/Configuration/TypoScript/setup.typoscript
diff --git a/typo3/sysext/form/Documentation/Concepts/Configuration/Index.rst b/typo3/sysext/form/Documentation/Concepts/Configuration/Index.rst
index 61ebe0f76e885c2adb295ee54c35ccc89716bb61..baee38cfb15090459021af7b8d906a1a68e48bf6 100644
--- a/typo3/sysext/form/Documentation/Concepts/Configuration/Index.rst
+++ b/typo3/sysext/form/Documentation/Concepts/Configuration/Index.rst
@@ -140,12 +140,12 @@ configuration of the backend ``module.tx_[pluginkey]`` is used.
 There are different ways to include the TypoScript configuration for the
 backend:
 
-- a) use a file called `ext_typoscript_setup.txt`,
+- a) use a file called `ext_typoscript_setup.typoscript`,
 - b) use the API function ``\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTypoScriptSetup()``,
 - c) add the configuration to your existing TypoScript template.
 
 We recommend using methods a and b. Here is why. The file
-:file:`ext_typoscript_setup.txt` can be stored within the root folder of
+:file:`ext_typoscript_setup.typoscript` can be stored within the root folder of
 your own site package. It will be automatically loaded in both frontend and
 backend of your TYPO3 installation. The API call (method b) does pretty
 much the same.
@@ -161,7 +161,7 @@ To sum it up: choose either method a or b, and you will be fine.
 
 .. _concepts-configuration-yamlregistration-backend-ext_typoscript_setup.txt:
 
-YAML registration for the backend via ext_typoscript_setup.txt
+YAML registration for the backend via ext_typoscript_setup.typoscript
 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 .. code-block:: typoscript
diff --git a/typo3/sysext/form/Documentation/FAQ/Index.rst b/typo3/sysext/form/Documentation/FAQ/Index.rst
index 0dedfd13ea5952ae62e9954e631337dd8c7f1d32..8e6b9182bdf91c66325fbbd1b9f452dc8144ded1 100644
--- a/typo3/sysext/form/Documentation/FAQ/Index.rst
+++ b/typo3/sysext/form/Documentation/FAQ/Index.rst
@@ -25,7 +25,7 @@ sitepackage ``EXT:my_site_package`` which contains your whole frontend
 integration.
 
 
-EXT:my_site_package/Configuration/TypoScript/setup.txt
+EXT:my_site_package/Configuration/TypoScript/setup.typoscript
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 First of all, register a new EXT:form configuration for the frontend via
@@ -73,12 +73,12 @@ Next, define the additional fluid template search paths via YAML.
    templates, register the new paths for the backend module as well.
 
 
-EXT:my_site_package/ext_typoscript_setup.txt
+EXT:my_site_package/ext_typoscript_setup.typoscript
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Register your EXT:form configuration for the backend via TypoScript. Read
 the :ref:`chapter <concepts-configuration-yamlregistration-backend>` to
-learn why we recommend using the concept behind ``ext_typoscript_setup.txt``.
+learn why we recommend using the concept behind ``ext_typoscript_setup.typoscript``.
 
 .. code-block:: typoscript
 
@@ -182,4 +182,4 @@ string which will be shown as the first select-option. If both settings exist,
 the :yaml:`defaultValue` is prioritized.
 
 Learn more :ref:`here<typo3.cms.form.prototypes.\<prototypeIdentifier>.formelementsdefinition.\<formelementtypeidentifier>.defaultValue>`
-and see the forge issue `#82422 <https://forge.typo3.org/issues/82422#note-6>`_.
\ No newline at end of file
+and see the forge issue `#82422 <https://forge.typo3.org/issues/82422#note-6>`_.
diff --git a/typo3/sysext/form/ext_localconf.php b/typo3/sysext/form/ext_localconf.php
index bdb4d7da19c8379be88c7dd646493b634e5b0e0a..f0224f5cb224f6fba2430a83c7a8ce39ce0f8cd8 100644
--- a/typo3/sysext/form/ext_localconf.php
+++ b/typo3/sysext/form/ext_localconf.php
@@ -17,7 +17,7 @@ call_user_func(function () {
 
     // Add new content element wizard entry
     \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig(
-        '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:form/Configuration/PageTS/modWizards.ts">'
+        '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:form/Configuration/PageTS/modWizards.tsconfig">'
     );
 
     // Add module configuration
diff --git a/typo3/sysext/frontend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.txt b/typo3/sysext/frontend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.tsconfig
similarity index 100%
rename from typo3/sysext/frontend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.txt
rename to typo3/sysext/frontend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.tsconfig
diff --git a/typo3/sysext/frontend/Configuration/TSconfig/Page/TCEFORM.txt b/typo3/sysext/frontend/Configuration/TSconfig/Page/TCEFORM.tsconfig
similarity index 100%
rename from typo3/sysext/frontend/Configuration/TSconfig/Page/TCEFORM.txt
rename to typo3/sysext/frontend/Configuration/TSconfig/Page/TCEFORM.tsconfig
diff --git a/typo3/sysext/frontend/Tests/Functional/Rendering/LocalizedContentRenderingTest.php b/typo3/sysext/frontend/Tests/Functional/Rendering/LocalizedContentRenderingTest.php
index dbf52cff632cd272f8b5206572407e21fdb793c7..a8e35c47641804b270a7fc2d6fc8365a168b0360 100644
--- a/typo3/sysext/frontend/Tests/Functional/Rendering/LocalizedContentRenderingTest.php
+++ b/typo3/sysext/frontend/Tests/Functional/Rendering/LocalizedContentRenderingTest.php
@@ -109,7 +109,7 @@ class LocalizedContentRenderingTest extends \TYPO3\CMS\Core\Tests\Functional\Dat
         $this->importScenarioDataSet('LiveDefaultPages');
         $this->importScenarioDataSet('LiveDefaultElements');
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
         ]);
         $this->backendUser->workspace = 0;
     }
diff --git a/typo3/sysext/frontend/ext_localconf.php b/typo3/sysext/frontend/ext_localconf.php
index e0d9561ebfafe6a269f4a7c2fceac00afaa58d4b..c10552e8bd5b8e06d81238c4b163eea79e143d50 100644
--- a/typo3/sysext/frontend/ext_localconf.php
+++ b/typo3/sysext/frontend/ext_localconf.php
@@ -108,9 +108,9 @@ $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['urlProcessing']['urlHandlers']['front
 
 // Include new content elements to modWizards
 \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig(
-    '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:frontend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.txt">'
+    '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:frontend/Configuration/TSconfig/Page/Mod/Wizards/NewContentElement.tsconfig">'
 );
 // Include FormEngine adjustments
 \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig(
-    '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:frontend/Configuration/TSconfig/Page/TCEFORM.txt">'
+    '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:frontend/Configuration/TSconfig/Page/TCEFORM.tsconfig">'
 );
diff --git a/typo3/sysext/indexed_search/Configuration/TypoScript/constants.txt b/typo3/sysext/indexed_search/Configuration/TypoScript/constants.typoscript
similarity index 100%
rename from typo3/sysext/indexed_search/Configuration/TypoScript/constants.txt
rename to typo3/sysext/indexed_search/Configuration/TypoScript/constants.typoscript
diff --git a/typo3/sysext/indexed_search/Configuration/TypoScript/setup.txt b/typo3/sysext/indexed_search/Configuration/TypoScript/setup.typoscript
similarity index 100%
rename from typo3/sysext/indexed_search/Configuration/TypoScript/setup.txt
rename to typo3/sysext/indexed_search/Configuration/TypoScript/setup.typoscript
diff --git a/typo3/sysext/linkvalidator/Configuration/TsConfig/Page/pagetsconfig.txt b/typo3/sysext/linkvalidator/Configuration/TsConfig/Page/pagetsconfig.tsconfig
similarity index 100%
rename from typo3/sysext/linkvalidator/Configuration/TsConfig/Page/pagetsconfig.txt
rename to typo3/sysext/linkvalidator/Configuration/TsConfig/Page/pagetsconfig.tsconfig
diff --git a/typo3/sysext/linkvalidator/ext_localconf.php b/typo3/sysext/linkvalidator/ext_localconf.php
index d1a89101e07aea967d6bab005b59d630900e2091..8f039aa29c9c6106c53a6c8669ec54df4dc8f847 100644
--- a/typo3/sysext/linkvalidator/ext_localconf.php
+++ b/typo3/sysext/linkvalidator/ext_localconf.php
@@ -2,7 +2,7 @@
 defined('TYPO3_MODE') or die();
 
 \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addPageTSConfig(
-    '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:linkvalidator/Configuration/TsConfig/Page/pagetsconfig.txt">'
+    '<INCLUDE_TYPOSCRIPT: source="FILE:EXT:linkvalidator/Configuration/TsConfig/Page/pagetsconfig.tsconfig">'
 );
 
 $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['scheduler']['tasks'][\TYPO3\CMS\Linkvalidator\Task\ValidatorTask::class] = [
diff --git a/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/Modify/ActionTest.php b/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/Modify/ActionTest.php
index 80e6bfd5549725afd714a1c36ede9094b6d57f86..928e568b65011c3208022dc8d220a0c452bb11bb 100644
--- a/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/Modify/ActionTest.php
+++ b/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/Modify/ActionTest.php
@@ -140,8 +140,8 @@ class ActionTest extends \TYPO3\CMS\Workspaces\Tests\Functional\DataHandling\Reg
         $this->assertAssertionDataSet('copyContentToLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageId, self::VALUE_BackendUserId, self::VALUE_WorkspaceId)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()
@@ -158,8 +158,8 @@ class ActionTest extends \TYPO3\CMS\Workspaces\Tests\Functional\DataHandling\Reg
         $this->assertAssertionDataSet('copyContentToLanguageFromNonDefaultLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageIdSecond, self::VALUE_BackendUserId, self::VALUE_WorkspaceId)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()
diff --git a/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/Publish/ActionTest.php b/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/Publish/ActionTest.php
index 103c7216de4b7375abf9c071c69f3f8b7de03355..32fff04bfdd2434dc53c7ffeb4dcc33cd63a460b 100644
--- a/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/Publish/ActionTest.php
+++ b/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/Publish/ActionTest.php
@@ -159,8 +159,8 @@ class ActionTest extends \TYPO3\CMS\Workspaces\Tests\Functional\DataHandling\Reg
         $this->assertAssertionDataSet('copyContentToLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageId)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()
@@ -178,8 +178,8 @@ class ActionTest extends \TYPO3\CMS\Workspaces\Tests\Functional\DataHandling\Reg
         $this->assertAssertionDataSet('copyContentToLanguageFromNonDefaultLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageIdSecond)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()
diff --git a/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/PublishAll/ActionTest.php b/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/PublishAll/ActionTest.php
index dde22e85c205ab5b941c94ac95b5f75e7ddd7fe5..b28281c13302266080bdaab48f7cc6acccfc1230 100644
--- a/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/PublishAll/ActionTest.php
+++ b/typo3/sysext/workspaces/Tests/Functional/DataHandling/Regular/PublishAll/ActionTest.php
@@ -148,8 +148,8 @@ class ActionTest extends \TYPO3\CMS\Workspaces\Tests\Functional\DataHandling\Reg
         $this->assertAssertionDataSet('copyContentToLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageId)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()
@@ -167,8 +167,8 @@ class ActionTest extends \TYPO3\CMS\Workspaces\Tests\Functional\DataHandling\Reg
         $this->assertAssertionDataSet('copyContentToLanguageFromNonDefaultLanguage');
 
         $this->setUpFrontendRootPage(1, [
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.ts',
-            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.ts'
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRenderer.typoscript',
+            'typo3/sysext/core/Tests/Functional/Fixtures/Frontend/JsonRendererNoOverlay.typoscript'
         ]);
         $responseSections = $this->getFrontendResponse(self::VALUE_PageId, self::VALUE_LanguageIdSecond)->getResponseSections();
         $this->assertThat($responseSections, $this->getRequestSectionHasRecordConstraint()