[DOCS] Exclude form finisher options from overrides

The documentation describes how to exclude specific options
from being overridden via the form plugin.

Resolves: #80407
Releases: master, 10.4
Change-Id: Id90808b921afadc3d090078e6d2cc5eb157fcf43
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70538


Tested-by: Mathias Brodala <mbrodala@pagemachine.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: waldhacker <hello@waldhacker.dev>
Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: waldhacker <hello@waldhacker.dev>

typo3/sysext/form/Documentation/I/Concepts/FormPlugin/Index.rst

@@ -7,12 +7,12 @@ Form plugin
 ===========
 
 
-.. _concepts-formelugin-general:
+.. _concepts-formplugin-general:
 
 What does it do?
 ----------------
 
-The form plugin allows you to assign a form - created with the ``form
+The ``form plugin`` allows you to assign a form - created with the ``form
 editor`` or shipped with your extension - to a specific page. This enables
 you to re-use forms throughout the whole TYPO3 installation. Furthermore, it
 offers the backend editor the possibility to override certain aspects of the
@@ -21,13 +21,43 @@ possibilities depend on the configuration of the underlying prototype.
 
 Imagine, your form contains a redirect finisher. The redirect target is set
 globally and valid for the whole ``form definition`` . While adding the form
-to a specific page, the backend editor can define a different redirect targeting. This
+to a specific page, the backend editor can define a different redirect target. This
 setting is only valid for the page containing the plugin.
 
 Read more about changing the :ref:`general<typo3.cms.form.prototypes.\<prototypeidentifier>.formengine>`
 and :ref:`aspect-specific form plugin configuration<typo3.cms.form.prototypes.\<prototypeIdentifier>.finishersdefinition.\<finisheridentifier>.formengine>`.
 
 
+.. _concepts-formplugin-exclude-override:
+
+Exclude options from overrides
+------------------------------
+
+Sometimes, it is useful to exclude specific options from being overridden via the
+form plugin. This can be achieved by unsetting the options concerned in your
+custom YAML configuration. For unsetting options use the YAML NULL (:yaml:`~`) value.
+
+The following example unsets four fields of the ``EmailToReceiver`` finisher. The
+options will only be removed from the form plugin. The Form editor is not affected
+by this.
+
+.. code-block:: yaml
+
+   TYPO3:
+     CMS:
+       Form:
+         prototypes:
+           standard:
+             finishersDefinition:
+               EmailToReceiver:
+                 FormEngine:
+                   elements:
+                     senderAddress: ~
+                     senderName: ~
+                     replyToAddress: ~
+                     translation: ~
+
+
 .. _concepts-formplugin-translation-formengine:
 
 Translation of form plugin
@@ -75,7 +105,7 @@ Imagine, the following is defined for an option value:
 
 First of all, the process searches for the translation key
 ``tt_content.finishersDefinition.EmailToReceiver.label`` within the file
-20: 'EXT:my_site_package/Resources/Private/Language/Database.xlf' and after
-it inside the file 10: 'EXT:form/Resources/Private/Language/Database.xlf'
+``20: 'EXT:my_site_package/Resources/Private/Language/Database.xlf'`` and
+afterwards inside the file 10: 'EXT:form/Resources/Private/Language/Database.xlf'
 (loaded by default). If nothing is found, the option value will be
 displayed unmodified.