diff --git a/composer/Plugin/ProjectMessage/Message.php b/composer/Plugin/ProjectMessage/Message.php
index b0cea11b929978474130dc219e2b54d8f70331d2..34bfd12e5e33db96e51de8fa8c22fa0aa7d12436 100644
--- a/composer/Plugin/ProjectMessage/Message.php
+++ b/composer/Plugin/ProjectMessage/Message.php
@@ -6,6 +6,8 @@
 
 /**
  * Determine configuration.
+ *
+ * @internal
  */
 class Message {
 
diff --git a/composer/Plugin/ProjectMessage/MessagePlugin.php b/composer/Plugin/ProjectMessage/MessagePlugin.php
index 5e4f6614a521b9cf11eb17050e60d91ee651af32..8a5333d8f1ca6bfbbf7d6e8e71a30f8aae17c83e 100644
--- a/composer/Plugin/ProjectMessage/MessagePlugin.php
+++ b/composer/Plugin/ProjectMessage/MessagePlugin.php
@@ -11,6 +11,8 @@
 
 /**
  * A Composer plugin to display a message after creating a project.
+ *
+ * @internal
  */
 class MessagePlugin implements PluginInterface, EventSubscriberInterface {
 
diff --git a/composer/Plugin/Scaffold/AllowedPackages.php b/composer/Plugin/Scaffold/AllowedPackages.php
index ca46d62dd17c261eb520d5fa7b3e487635f6c7a4..9b28368bbd45781da507b6ebae512345c7c325e0 100644
--- a/composer/Plugin/Scaffold/AllowedPackages.php
+++ b/composer/Plugin/Scaffold/AllowedPackages.php
@@ -12,6 +12,8 @@
  *
  * If the root-level composer.json allows drupal/core, and drupal/core allows
  * drupal/assets, then the later package will also implicitly be allowed.
+ *
+ * @internal
  */
 class AllowedPackages implements PostPackageEventListenerInterface {
 
diff --git a/composer/Plugin/Scaffold/CommandProvider.php b/composer/Plugin/Scaffold/CommandProvider.php
index b13a48c5ed7479d3a9af838d573b978736cd4ac1..6597039399bb93cc80ea908caf692aa4c8ec06a2 100644
--- a/composer/Plugin/Scaffold/CommandProvider.php
+++ b/composer/Plugin/Scaffold/CommandProvider.php
@@ -6,6 +6,8 @@
 
 /**
  * List of all commands provided by this package.
+ *
+ * @internal
  */
 class CommandProvider implements CommandProviderCapability {
 
diff --git a/composer/Plugin/Scaffold/ComposerScaffoldCommand.php b/composer/Plugin/Scaffold/ComposerScaffoldCommand.php
index fd8becb3d075472b47d0c29f263e2aa9aa67b63e..6de8aa4bf8fc7743f43368ee28783835b5c75843 100644
--- a/composer/Plugin/Scaffold/ComposerScaffoldCommand.php
+++ b/composer/Plugin/Scaffold/ComposerScaffoldCommand.php
@@ -11,6 +11,8 @@
  *
  * Manually run the scaffold operation that normally happens after
  * 'composer install'.
+ *
+ * @internal
  */
 class ComposerScaffoldCommand extends BaseCommand {
 
diff --git a/composer/Plugin/Scaffold/GenerateAutoloadReferenceFile.php b/composer/Plugin/Scaffold/GenerateAutoloadReferenceFile.php
index cfbd6c1523bddf331f75dbc34a4da3fb7fc6a4bc..ba27bef99cf9694c2808c0b15269057ec8867ab4 100644
--- a/composer/Plugin/Scaffold/GenerateAutoloadReferenceFile.php
+++ b/composer/Plugin/Scaffold/GenerateAutoloadReferenceFile.php
@@ -8,6 +8,8 @@
 
 /**
  * Generates an 'autoload.php' that includes the autoloader created by Composer.
+ *
+ * @internal
  */
 final class GenerateAutoloadReferenceFile {
 
diff --git a/composer/Plugin/Scaffold/Git.php b/composer/Plugin/Scaffold/Git.php
index 779b8f034b2013306f29c161433115597cae7f97..015e472eb2448393f06fe19c5213d1fc04dfd207 100644
--- a/composer/Plugin/Scaffold/Git.php
+++ b/composer/Plugin/Scaffold/Git.php
@@ -7,6 +7,8 @@
 
 /**
  * Provide some Git utility operations
+ *
+ * @internal
  */
 class Git {
 
diff --git a/composer/Plugin/Scaffold/Handler.php b/composer/Plugin/Scaffold/Handler.php
index 68410a681497625250af2f5a894f0045113d68f4..0e1b75665d49877397921bedd2d3a1fa42469507 100644
--- a/composer/Plugin/Scaffold/Handler.php
+++ b/composer/Plugin/Scaffold/Handler.php
@@ -17,6 +17,8 @@
  *
  * Contains the primary logic which determines the files to be fetched and
  * processed.
+ *
+ * @internal
  */
 class Handler {
 
diff --git a/composer/Plugin/Scaffold/Interpolator.php b/composer/Plugin/Scaffold/Interpolator.php
index 3c8cad839b78a76de56b43966e168175eeae67cb..c9f6a4fedb571ec1f084dfe2ca9a05132a2ae6a8 100644
--- a/composer/Plugin/Scaffold/Interpolator.php
+++ b/composer/Plugin/Scaffold/Interpolator.php
@@ -4,6 +4,8 @@
 
 /**
  * Injects config values from an associative array into a string.
+ *
+ * @internal
  */
 class Interpolator {
 
diff --git a/composer/Plugin/Scaffold/ManageGitIgnore.php b/composer/Plugin/Scaffold/ManageGitIgnore.php
index 5f1bb9dc9574a69cd802589eda6adae1f2e49af0..dcb03fafcb8061b2deddd2202403028182791cda 100644
--- a/composer/Plugin/Scaffold/ManageGitIgnore.php
+++ b/composer/Plugin/Scaffold/ManageGitIgnore.php
@@ -6,6 +6,8 @@
 
 /**
  * Manage the .gitignore file.
+ *
+ * @internal
  */
 class ManageGitIgnore {
 
diff --git a/composer/Plugin/Scaffold/ManageOptions.php b/composer/Plugin/Scaffold/ManageOptions.php
index d54cf017bfc2bb5d02b2f8b41cf333441b61ab33..56cb1a0a1a487743e8a0d8d82c88805aa3cfaa71 100644
--- a/composer/Plugin/Scaffold/ManageOptions.php
+++ b/composer/Plugin/Scaffold/ManageOptions.php
@@ -12,6 +12,8 @@
  * Projects that describe scaffold files do so via their scaffold options.
  * This data is pulled from the 'drupal-scaffold' portion of the extras
  * section of the project data.
+ *
+ * @internal
  */
 class ManageOptions {
 
diff --git a/composer/Plugin/Scaffold/Operations/AbstractOperation.php b/composer/Plugin/Scaffold/Operations/AbstractOperation.php
index 5f7261fd262c499593e1c6abff018f4e9760a217..96bd5904d0094537d1cef0c1765259d630f7435a 100644
--- a/composer/Plugin/Scaffold/Operations/AbstractOperation.php
+++ b/composer/Plugin/Scaffold/Operations/AbstractOperation.php
@@ -6,6 +6,8 @@
 
 /**
  * Provides default behaviors for operations.
+ *
+ * @internal
  */
 abstract class AbstractOperation implements OperationInterface {
 
diff --git a/composer/Plugin/Scaffold/Operations/AppendOp.php b/composer/Plugin/Scaffold/Operations/AppendOp.php
index 7f5c7e8b0dbe288a7968ef89db4280f9a8fbc897..802b474bb6deab3e417777037a42bba0cb881875 100644
--- a/composer/Plugin/Scaffold/Operations/AppendOp.php
+++ b/composer/Plugin/Scaffold/Operations/AppendOp.php
@@ -8,6 +8,8 @@
 
 /**
  * Scaffold operation to add to the beginning and/or end of a scaffold file.
+ *
+ * @internal
  */
 class AppendOp extends AbstractOperation {
 
diff --git a/composer/Plugin/Scaffold/Operations/ConjunctionOp.php b/composer/Plugin/Scaffold/Operations/ConjunctionOp.php
index 83b2441271c7ed8266fab55f6954231b5ed5e52e..fbbb176b8aeeea4579894a1828559284206d128b 100644
--- a/composer/Plugin/Scaffold/Operations/ConjunctionOp.php
+++ b/composer/Plugin/Scaffold/Operations/ConjunctionOp.php
@@ -8,6 +8,8 @@
 
 /**
  * Joins two operations on the same file into a single operation.
+ *
+ * @internal
  */
 class ConjunctionOp extends AbstractOperation {
 
diff --git a/composer/Plugin/Scaffold/Operations/OperationData.php b/composer/Plugin/Scaffold/Operations/OperationData.php
index 66b85229aed412b4839d183a61100ee92fb28801..9aa73611c06874f1928e6b3e8ad41b5979b8eb20 100644
--- a/composer/Plugin/Scaffold/Operations/OperationData.php
+++ b/composer/Plugin/Scaffold/Operations/OperationData.php
@@ -4,6 +4,8 @@
 
 /**
  * Holds parameter data for operation objects during operation creation only.
+ *
+ * @internal
  */
 class OperationData {
 
diff --git a/composer/Plugin/Scaffold/Operations/OperationFactory.php b/composer/Plugin/Scaffold/Operations/OperationFactory.php
index 7742e4bb9d7f1f1cd4ab2167dbccdd4c387ba290..b256e0e15fbaafd5883807181af28827e0b9b805 100644
--- a/composer/Plugin/Scaffold/Operations/OperationFactory.php
+++ b/composer/Plugin/Scaffold/Operations/OperationFactory.php
@@ -8,6 +8,8 @@
 
 /**
  * Create Scaffold operation objects based on provided metadata.
+ *
+ * @internal
  */
 class OperationFactory {
 
diff --git a/composer/Plugin/Scaffold/Operations/OperationInterface.php b/composer/Plugin/Scaffold/Operations/OperationInterface.php
index 409b4761a2a9e8072d6045bcb38bf5c045abf4b5..4b57c74353670f859429c63e49efc4c109947f75 100644
--- a/composer/Plugin/Scaffold/Operations/OperationInterface.php
+++ b/composer/Plugin/Scaffold/Operations/OperationInterface.php
@@ -8,6 +8,8 @@
 
 /**
  * Interface for scaffold operation objects.
+ *
+ * @internal
  */
 interface OperationInterface {
 
diff --git a/composer/Plugin/Scaffold/Operations/ReplaceOp.php b/composer/Plugin/Scaffold/Operations/ReplaceOp.php
index 5b4c4b9b1d88226de8f3060e2a1fdc8876bee89f..9f3eba09634dcf1048bf639c774a847a6a365734 100644
--- a/composer/Plugin/Scaffold/Operations/ReplaceOp.php
+++ b/composer/Plugin/Scaffold/Operations/ReplaceOp.php
@@ -9,6 +9,8 @@
 
 /**
  * Scaffold operation to copy or symlink from source to destination.
+ *
+ * @internal
  */
 class ReplaceOp extends AbstractOperation {
 
diff --git a/composer/Plugin/Scaffold/Operations/ScaffoldFileCollection.php b/composer/Plugin/Scaffold/Operations/ScaffoldFileCollection.php
index c000e64a478ebc797da5e58a5fbbfd9b88fb0088..59cc93c3612f7b0921a6bd07ea37f4683149b51a 100644
--- a/composer/Plugin/Scaffold/Operations/ScaffoldFileCollection.php
+++ b/composer/Plugin/Scaffold/Operations/ScaffoldFileCollection.php
@@ -10,6 +10,8 @@
 
 /**
  * Collection of scaffold files.
+ *
+ * @internal
  */
 class ScaffoldFileCollection implements \IteratorAggregate {
 
diff --git a/composer/Plugin/Scaffold/Operations/ScaffoldResult.php b/composer/Plugin/Scaffold/Operations/ScaffoldResult.php
index 3fc1699777a09eae7b7143699e4927aa548abf3e..3445b5307ff5f6f048592b5ebba454899d52b71b 100644
--- a/composer/Plugin/Scaffold/Operations/ScaffoldResult.php
+++ b/composer/Plugin/Scaffold/Operations/ScaffoldResult.php
@@ -6,6 +6,8 @@
 
 /**
  * Record the result of a scaffold operation.
+ *
+ * @internal
  */
 class ScaffoldResult {
 
diff --git a/composer/Plugin/Scaffold/Operations/SkipOp.php b/composer/Plugin/Scaffold/Operations/SkipOp.php
index 3e6c111bdfcbb7aceb7008ea17538f77916f97da..b9f81085c7d4c6f9c357983b7fa4b1f1cfa253d3 100644
--- a/composer/Plugin/Scaffold/Operations/SkipOp.php
+++ b/composer/Plugin/Scaffold/Operations/SkipOp.php
@@ -8,6 +8,8 @@
 
 /**
  * Scaffold operation to skip a scaffold file (do nothing).
+ *
+ * @internal
  */
 class SkipOp extends AbstractOperation {
 
diff --git a/composer/Plugin/Scaffold/Plugin.php b/composer/Plugin/Scaffold/Plugin.php
index e440c5dcc61be382ca88e41f26c8913a03e22db5..a1252cfac140bd4f5483f223b8346efda8a28836 100644
--- a/composer/Plugin/Scaffold/Plugin.php
+++ b/composer/Plugin/Scaffold/Plugin.php
@@ -18,6 +18,8 @@
 
 /**
  * Composer plugin for handling drupal scaffold.
+ *
+ * @internal
  */
 class Plugin implements PluginInterface, EventSubscriberInterface, Capable {
 
diff --git a/composer/Plugin/Scaffold/PostPackageEventListenerInterface.php b/composer/Plugin/Scaffold/PostPackageEventListenerInterface.php
index 702ab0f54ba5f287467358b28008a5c944e1ec1b..61356b145cf59e6ec2916895fa37f3d4402857d6 100644
--- a/composer/Plugin/Scaffold/PostPackageEventListenerInterface.php
+++ b/composer/Plugin/Scaffold/PostPackageEventListenerInterface.php
@@ -8,6 +8,8 @@
  * Interface for post package event listeners.
  *
  * @see \Drupal\Composer\Plugin\Scaffold\Handler::onPostPackageEvent
+ *
+ * @internal
  */
 interface PostPackageEventListenerInterface {
 
diff --git a/composer/Plugin/Scaffold/ScaffoldFileInfo.php b/composer/Plugin/Scaffold/ScaffoldFileInfo.php
index 95cba8ba2d89ce7e2e802d73b273bd76454292b2..94e35e5bc2c5ec1596a96e0100de025b38192aaa 100644
--- a/composer/Plugin/Scaffold/ScaffoldFileInfo.php
+++ b/composer/Plugin/Scaffold/ScaffoldFileInfo.php
@@ -12,6 +12,8 @@
  * scaffold file also has an 'operation' object that controls how the scaffold
  * file will be placed (e.g. via copy or symlink, or maybe by appending multiple
  * files together). The operation may have one or more source files.
+ *
+ * @internal
  */
 class ScaffoldFileInfo {
 
diff --git a/composer/Plugin/Scaffold/ScaffoldFilePath.php b/composer/Plugin/Scaffold/ScaffoldFilePath.php
index f225a226282ff36f2a6a7165249874b933bed6cc..5fb5af41d0acf1962b2ce8ee91c383cd32e96563 100644
--- a/composer/Plugin/Scaffold/ScaffoldFilePath.php
+++ b/composer/Plugin/Scaffold/ScaffoldFilePath.php
@@ -15,6 +15,8 @@
  * source files used to create them. Static factory methods named
  * destinationPath and sourcePath, respectively, are provided to create
  * ScaffoldFilePath objects.
+ *
+ * @internal
  */
 class ScaffoldFilePath {
 
diff --git a/composer/Plugin/Scaffold/ScaffoldOptions.php b/composer/Plugin/Scaffold/ScaffoldOptions.php
index 0a963c788d638957ad9e03ca3082b86d146dad1e..05cd864245de570c088624e7e0a19c3cf441944b 100644
--- a/composer/Plugin/Scaffold/ScaffoldOptions.php
+++ b/composer/Plugin/Scaffold/ScaffoldOptions.php
@@ -8,6 +8,8 @@
  * Projects that describe scaffold files do so via their scaffold options. This
  * data is pulled from the 'drupal-scaffold' portion of the extras section of
  * the project data.
+ *
+ * @internal
  */
 class ScaffoldOptions {
 
diff --git a/composer/Plugin/VendorHardening/Config.php b/composer/Plugin/VendorHardening/Config.php
index 2d1cef5feab3e8c7273b5b594fdcdc5a061e970c..d468b03d2366640b8255a55b11683701939a26c2 100644
--- a/composer/Plugin/VendorHardening/Config.php
+++ b/composer/Plugin/VendorHardening/Config.php
@@ -9,6 +9,8 @@
  *
  * Default configuration is merged with the root package's
  * extra:drupal-core-vendor-hardening configuration.
+ *
+ * @internal
  */
 class Config {
 
diff --git a/composer/Plugin/VendorHardening/FileSecurity.php b/composer/Plugin/VendorHardening/FileSecurity.php
index c8bcd6d328dae6ff209cce34d1cbaf6313a424c2..c6f5b90c5b706ee8bfa856f406eb113c96ab3fd7 100644
--- a/composer/Plugin/VendorHardening/FileSecurity.php
+++ b/composer/Plugin/VendorHardening/FileSecurity.php
@@ -8,6 +8,8 @@
  * IMPORTANT: This file is duplicated at /lib/Drupal/Component/FileSecurity.
  * If any change is made here, the same change should be made in the duplicate.
  * See https://www.drupal.org/project/drupal/issues/3079481.
+ *
+ * @internal
  */
 class FileSecurity {
 
diff --git a/composer/Plugin/VendorHardening/VendorHardeningPlugin.php b/composer/Plugin/VendorHardening/VendorHardeningPlugin.php
index 373b0654c8cbfd610f440224c897f5217e9906c4..c8e6182e113ce18b8ed558020c87fc1ac3927bb4 100644
--- a/composer/Plugin/VendorHardening/VendorHardeningPlugin.php
+++ b/composer/Plugin/VendorHardening/VendorHardeningPlugin.php
@@ -21,6 +21,8 @@
  * directory within an HTTP server's docroot.
  *
  * @see https://www.drupal.org/docs/develop/using-composer/using-drupals-vendor-cleanup-composer-plugin
+ *
+ * @internal
  */
 class VendorHardeningPlugin implements PluginInterface, EventSubscriberInterface {