diff --git a/typo3/sysext/backend/Classes/View/BackendLayout/ContentFetcher.php b/typo3/sysext/backend/Classes/View/BackendLayout/ContentFetcher.php
index 4a5785f4f0c902871965e71650f410294e68cf47..7a319924992c7c74ec147ffe9a8e6bbb1db97745 100644
--- a/typo3/sysext/backend/Classes/View/BackendLayout/ContentFetcher.php
+++ b/typo3/sysext/backend/Classes/View/BackendLayout/ContentFetcher.php
@@ -40,6 +40,8 @@ use TYPO3\CMS\Core\Utility\GeneralUtility;
  * - Capable of returning all records in active language as flat array
  * - Capable of returning records for a given column in a given (optional) language
  * - Capable of returning translation data (brief info about translation consistency)
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 class ContentFetcher
 {
diff --git a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/AbstractGridObject.php b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/AbstractGridObject.php
index 6c9e8a377fbd0f1692e15d948d9cae643e03939a..ea7bff35bc32c0036c1a3a188724fb896564de49 100644
--- a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/AbstractGridObject.php
+++ b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/AbstractGridObject.php
@@ -34,6 +34,8 @@ use TYPO3\CMS\Core\Utility\StringUtility;
  * @see GridColumn
  * @see GridColumnItem
  * @see LanguageColumn
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 abstract class AbstractGridObject
 {
diff --git a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/Grid.php b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/Grid.php
index 38be6610672f1267b6b6eac85e0926d62e7968f8..c257d01743b2cf63fad9c57af2aa97f380c8a34d 100644
--- a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/Grid.php
+++ b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/Grid.php
@@ -32,6 +32,8 @@ namespace TYPO3\CMS\Backend\View\BackendLayout\Grid;
  *       - GridColumnItem (one per record)
  *
  * Accessed in Fluid templates.
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 class Grid extends AbstractGridObject
 {
diff --git a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridColumn.php b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridColumn.php
index fadfd6465c2dceacf4be066468027bc07957fb49..e1bc4d25f064878b636ead1c822aec1e8c34115b 100644
--- a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridColumn.php
+++ b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridColumn.php
@@ -34,6 +34,8 @@ use TYPO3\CMS\Core\Utility\GeneralUtility;
  * in the page layout.
  *
  * Accessed from Fluid templates.
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 class GridColumn extends AbstractGridObject
 {
diff --git a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridColumnItem.php b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridColumnItem.php
index e636f357b0ec74ede26f21cb4e7cda32589f7bf5..58e43396295d2bc2315b19f6cd54203a9bf5f9dc 100644
--- a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridColumnItem.php
+++ b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridColumnItem.php
@@ -36,6 +36,8 @@ use TYPO3\CMS\Core\Versioning\VersionState;
  * is-versioned, is-editable, is-delible and so on.
  *
  * Accessed from Fluid templates.
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 class GridColumnItem extends AbstractGridObject
 {
diff --git a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridRow.php b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridRow.php
index 9f4bdefb84ac628e84e5e68f827e9faba521ee2e..abdeb57532b6c7575c90af085e97dc9a5925c0e1 100644
--- a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridRow.php
+++ b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/GridRow.php
@@ -24,6 +24,8 @@ namespace TYPO3\CMS\Backend\View\BackendLayout\Grid;
  * Is solely responsible for grouping GridColumns.
  *
  * Accessed in Fluid templates.
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 class GridRow extends AbstractGridObject
 {
diff --git a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/LanguageColumn.php b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/LanguageColumn.php
index 9360dfd44e06b495fc7ec27f6bdbcd9a17246c05..1f9b0646a15c58957eedb5e5fdc20e56a1bdeb22 100644
--- a/typo3/sysext/backend/Classes/View/BackendLayout/Grid/LanguageColumn.php
+++ b/typo3/sysext/backend/Classes/View/BackendLayout/Grid/LanguageColumn.php
@@ -38,6 +38,8 @@ use TYPO3\CMS\Core\Versioning\VersionState;
  *
  * Accessed from Fluid templates - generated from within BackendLayout when
  * "page" module is in "languages" mode.
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 class LanguageColumn extends AbstractGridObject
 {
diff --git a/typo3/sysext/backend/Classes/View/BackendLayout/RecordRememberer.php b/typo3/sysext/backend/Classes/View/BackendLayout/RecordRememberer.php
index e9e9d11a1e03f1616071f75cf6a0e0b5ecce9cc0..c2afc4db4a6c8a722e6f17765c03ff17ff9f5927 100644
--- a/typo3/sysext/backend/Classes/View/BackendLayout/RecordRememberer.php
+++ b/typo3/sysext/backend/Classes/View/BackendLayout/RecordRememberer.php
@@ -19,6 +19,9 @@ namespace TYPO3\CMS\Backend\View\BackendLayout;
 
 use TYPO3\CMS\Core\SingletonInterface;
 
+/**
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
+ */
 class RecordRememberer implements SingletonInterface
 {
     /**
diff --git a/typo3/sysext/backend/Classes/View/Drawing/BackendLayoutRenderer.php b/typo3/sysext/backend/Classes/View/Drawing/BackendLayoutRenderer.php
index 8dd5eb60b3526e2bb190ba3b63bd6580e5a08fad..ceec77e2f6bd979fce262f8ad2f6a2895433275e 100644
--- a/typo3/sysext/backend/Classes/View/Drawing/BackendLayoutRenderer.php
+++ b/typo3/sysext/backend/Classes/View/Drawing/BackendLayoutRenderer.php
@@ -51,6 +51,8 @@ use TYPO3\CMS\Fluid\View\TemplateView;
  *
  * - Initializes the clipboard used in the page layout
  * - Inserts an encoded paste icon as JS which is made visible when clipboard elements are registered
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 class BackendLayoutRenderer
 {
diff --git a/typo3/sysext/backend/Classes/View/Drawing/DrawingConfiguration.php b/typo3/sysext/backend/Classes/View/Drawing/DrawingConfiguration.php
index 6cdcc814c750e7438fbf374f0b62b5aa09cbca88..1e0ea5358efd518443a6031cf2252f35bf016b35 100644
--- a/typo3/sysext/backend/Classes/View/Drawing/DrawingConfiguration.php
+++ b/typo3/sysext/backend/Classes/View/Drawing/DrawingConfiguration.php
@@ -29,6 +29,8 @@ use TYPO3\CMS\Core\Localization\LanguageService;
  * tt_content fields and CTypes.
  *
  * Corresponds to legacy public properties from PageLayoutView.
+ *
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
  */
 class DrawingConfiguration
 {
diff --git a/typo3/sysext/backend/Classes/View/PageLayoutContext.php b/typo3/sysext/backend/Classes/View/PageLayoutContext.php
index 7df86cca58940e9685214d2b0da031ce3e6eb2f1..b430589cee36e38e14b9cd60c1d905eaecf4950f 100644
--- a/typo3/sysext/backend/Classes/View/PageLayoutContext.php
+++ b/typo3/sysext/backend/Classes/View/PageLayoutContext.php
@@ -36,6 +36,9 @@ use TYPO3\CMS\Core\Site\SiteFinder;
 use TYPO3\CMS\Core\Type\Bitmask\Permission;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 
+/**
+ * @internal this is experimental and subject to change in TYPO3 v10 / v11
+ */
 class PageLayoutContext
 {
     /**