diff --git a/typo3/sysext/backend/Classes/Controller/File/FileController.php b/typo3/sysext/backend/Classes/Controller/File/FileController.php
index d62f3d1926ab..8d3f3deeffab 100644
--- a/typo3/sysext/backend/Classes/Controller/File/FileController.php
+++ b/typo3/sysext/backend/Classes/Controller/File/FileController.php
@@ -32,8 +32,6 @@
  * Gateway for TCE (TYPO3 Core Engine) file-handling through POST forms.
  * This script serves as the file administration part of the TYPO3 Core Engine.
  * Basically it includes two libraries which are used to manipulate files on the server.
- * Before TYPO3 4.3, it was located in typo3/tce_file.php and redirected back to a
- * $redirectURL. Since 4.3 this class is also used for accessing via AJAX
  */
 class FileController
 {
diff --git a/typo3/sysext/backend/Classes/Form/Element/SelectCheckBoxElement.php b/typo3/sysext/backend/Classes/Form/Element/SelectCheckBoxElement.php
index 1c33db9a5f01..ae6bf7a1e171 100644
--- a/typo3/sysext/backend/Classes/Form/Element/SelectCheckBoxElement.php
+++ b/typo3/sysext/backend/Classes/Form/Element/SelectCheckBoxElement.php
@@ -92,7 +92,7 @@ public function render()
                         ];
                     } else {
                         // Check if some help text is available
-                        // Since TYPO3 4.5 help text is expected to be an associative array
+                        // Help text is expected to be an associative array
                         // with two key, "title" and "description"
                         // For the sake of backwards compatibility, we test if the help text
                         // is a string and use it as a description (this could happen if items
diff --git a/typo3/sysext/backend/Classes/Utility/BackendUtility.php b/typo3/sysext/backend/Classes/Utility/BackendUtility.php
index c61bbbef59c5..0bf79b2da826 100644
--- a/typo3/sysext/backend/Classes/Utility/BackendUtility.php
+++ b/typo3/sysext/backend/Classes/Utility/BackendUtility.php
@@ -2417,8 +2417,6 @@ public static function helpText($table, $field)
     /**
      * API function that wraps the text / html in help text, so if a user hovers over it
      * the help text will show up
-     * This is the new help API function since TYPO3 4.5, and uses the new behaviour
-     * (hover over text, no icon, no fulltext option, no option to disable the help)
      *
      * @param string $table The table name for which the help should be shown
      * @param string $field The field name for which the help should be shown
diff --git a/typo3/sysext/core/Classes/Cache/Backend/AbstractBackend.php b/typo3/sysext/core/Classes/Cache/Backend/AbstractBackend.php
index 182ab2ea95ea..f9e38eedb26c 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/AbstractBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/AbstractBackend.php
@@ -20,7 +20,6 @@
 /**
  * An abstract caching backend
  *
- * This file is a backport from FLOW3
  * @api
  */
 abstract class AbstractBackend implements BackendInterface, LoggerAwareInterface
@@ -44,9 +43,8 @@ abstract class AbstractBackend implements BackendInterface, LoggerAwareInterface
     /**
      * The current application context
      *
-     * TYPO3 v4 note: This variable is currently unused in v4 context and set to
-     * "production" always. It is only kept to stay in sync with
-     * FLOW3 code.
+     * This variable is currently unused and set to "production" always.
+     * It is only kept to keep backwards compatibility.
      *
      * @var string
      */
@@ -62,7 +60,7 @@ abstract class AbstractBackend implements BackendInterface, LoggerAwareInterface
     /**
      * Constructs this backend
      *
-     * @param string $context FLOW3's application context
+     * @param string $context Unused, for backward compatibility only
      * @param array $options Configuration options - depends on the actual backend
      * @throws \InvalidArgumentException
      * @api
diff --git a/typo3/sysext/core/Classes/Cache/Backend/ApcBackend.php b/typo3/sysext/core/Classes/Cache/Backend/ApcBackend.php
index 125130d4d30e..4d770f7bca22 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/ApcBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/ApcBackend.php
@@ -34,7 +34,6 @@
  * This prefix makes sure that keys from the different installations do not
  * conflict.
  *
- * This file is a backport from FLOW3
  * @api
  */
 class ApcBackend extends \TYPO3\CMS\Core\Cache\Backend\AbstractBackend implements \TYPO3\CMS\Core\Cache\Backend\TaggableBackendInterface
@@ -69,7 +68,7 @@ protected function getIdentifierPrefix()
     /**
      * Constructs this backend
      *
-     * @param string $context FLOW3's application context
+     * @param string $context Unused, for backward compatibility only
      * @param array $options Configuration options - unused here
      * @throws \TYPO3\CMS\Core\Cache\Exception
      */
diff --git a/typo3/sysext/core/Classes/Cache/Backend/ApcuBackend.php b/typo3/sysext/core/Classes/Cache/Backend/ApcuBackend.php
index bdb262092077..ff6473732855 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/ApcuBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/ApcuBackend.php
@@ -71,7 +71,7 @@ protected function getIdentifierPrefix()
     /**
      * Constructs this backend
      *
-     * @param string $context FLOW3's application context
+     * @param string $context Unused, for backward compatibility only
      * @param array $options Configuration options - unused here
      * @throws Cache\Exception
      */
diff --git a/typo3/sysext/core/Classes/Cache/Backend/FileBackend.php b/typo3/sysext/core/Classes/Cache/Backend/FileBackend.php
index 27ddeb297a89..0c98c1bd5edd 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/FileBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/FileBackend.php
@@ -21,7 +21,6 @@
 /**
  * A caching backend which stores cache entries in files
  *
- * This file is a backport from FLOW3
  * @api
  */
 class FileBackend extends \TYPO3\CMS\Core\Cache\Backend\SimpleFileBackend implements \TYPO3\CMS\Core\Cache\Backend\FreezableBackendInterface, \TYPO3\CMS\Core\Cache\Backend\TaggableBackendInterface
@@ -98,10 +97,6 @@ public function isFrozen()
      * This method also detects if this backend is frozen and sets the internal
      * flag accordingly.
      *
-     * TYPO3 v4 note: This method is different between TYPO3 v4 and FLOW3
-     * because the Environment class to get the path to a temporary directory
-     * does not exist in v4.
-     *
      * @param \TYPO3\CMS\Core\Cache\Frontend\FrontendInterface $cache The cache frontend
      */
     public function setCache(\TYPO3\CMS\Core\Cache\Frontend\FrontendInterface $cache)
diff --git a/typo3/sysext/core/Classes/Cache/Backend/FreezableBackendInterface.php b/typo3/sysext/core/Classes/Cache/Backend/FreezableBackendInterface.php
index f0125840ee83..dc72335493b4 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/FreezableBackendInterface.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/FreezableBackendInterface.php
@@ -1,15 +1,19 @@
 <?php
 namespace TYPO3\CMS\Core\Cache\Backend;
 
-/*                                                                        *
- * This script belongs to the FLOW3 framework.                            *
- *                                                                        *
- * It is free software; you can redistribute it and/or modify it under    *
- * the terms of the GNU Lesser General Public License, either version 3   *
- * of the License, or (at your option) any later version.                 *
- *                                                                        *
- * The TYPO3 project - inspiring people to share!                         *
- *                                                                        */
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
 /**
  * A contract for a cache backend which can be frozen.
  *
diff --git a/typo3/sysext/core/Classes/Cache/Backend/MemcachedBackend.php b/typo3/sysext/core/Classes/Cache/Backend/MemcachedBackend.php
index 1c656bddbbb3..b215ae482a8f 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/MemcachedBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/MemcachedBackend.php
@@ -40,7 +40,6 @@
  * Note: When using the Memcached backend to store values of more than ~1 MB,
  * the data will be split into chunks to make them fit into the memcached limits.
  *
- * This file is a backport from FLOW3 by Ingo Renner.
  * @api
  */
 class MemcachedBackend extends AbstractBackend implements TaggableBackendInterface, TransientBackendInterface
@@ -91,7 +90,7 @@ class MemcachedBackend extends AbstractBackend implements TaggableBackendInterfa
     /**
      * Constructs this backend
      *
-     * @param string $context FLOW3's application context
+     * @param string $context Unused, for backward compatibility only
      * @param array $options Configuration options - depends on the actual backend
      * @throws Exception if memcache is not installed
      */
diff --git a/typo3/sysext/core/Classes/Cache/Backend/NullBackend.php b/typo3/sysext/core/Classes/Cache/Backend/NullBackend.php
index 485131262b60..76d84aea09f4 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/NullBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/NullBackend.php
@@ -17,7 +17,6 @@
 /**
  * A caching backend which forgets everything immediately
  *
- * This file is a backport from FLOW3
  * @api
  */
 class NullBackend extends \TYPO3\CMS\Core\Cache\Backend\AbstractBackend implements \TYPO3\CMS\Core\Cache\Backend\PhpCapableBackendInterface, \TYPO3\CMS\Core\Cache\Backend\TaggableBackendInterface
diff --git a/typo3/sysext/core/Classes/Cache/Backend/RedisBackend.php b/typo3/sysext/core/Classes/Cache/Backend/RedisBackend.php
index 2173fd2ac46f..9598807ed1e3 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/RedisBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/RedisBackend.php
@@ -132,7 +132,7 @@ class RedisBackend extends AbstractBackend implements TaggableBackendInterface
     /**
      * Construct this backend
      *
-     * @param string $context FLOW3's application context
+     * @param string $context Unused, for backward compatibility only
      * @param array $options Configuration options
      * @throws \TYPO3\CMS\Core\Cache\Exception if php redis module is not loaded
      */
diff --git a/typo3/sysext/core/Classes/Cache/Backend/SimpleFileBackend.php b/typo3/sysext/core/Classes/Cache/Backend/SimpleFileBackend.php
index 4cb6b3d135ed..f300592d89c4 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/SimpleFileBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/SimpleFileBackend.php
@@ -1,15 +1,18 @@
 <?php
 namespace TYPO3\CMS\Core\Cache\Backend;
 
-/*                                                                        *
- * This script belongs to the FLOW3 framework.                            *
- *                                                                        *
- * It is free software; you can redistribute it and/or modify it under    *
- * the terms of the GNU Lesser General Public License, either version 3   *
- * of the License, or (at your option) any later version.                 *
- *                                                                        *
- * The TYPO3 project - inspiring people to share!                         *
- *                                                                        */
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
 
 use TYPO3\CMS\Core\Service\OpcodeCacheService;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
@@ -35,7 +38,6 @@ class SimpleFileBackend extends \TYPO3\CMS\Core\Cache\Backend\AbstractBackend im
     protected $cacheDirectory = '';
 
     /**
-     * TYPO3 v4 note: This variable is only available in v5
      * Temporary path to cache directory before setCache() was called. It is
      * set by setCacheDirectory() and used in setCache() method which calls
      * the directory creation if needed. The variable is not used afterwards,
@@ -66,10 +68,6 @@ class SimpleFileBackend extends \TYPO3\CMS\Core\Cache\Backend\AbstractBackend im
      * Sets a reference to the cache frontend which uses this backend and
      * initializes the default cache directory.
      *
-     * TYPO3 v4 note: This method is different between TYPO3 v4 and FLOW3
-     * because the Environment class to get the path to a temporary directory
-     * does not exist in v4.
-     *
      * @param \TYPO3\CMS\Core\Cache\Frontend\FrontendInterface $cache The cache frontend
      * @throws \TYPO3\CMS\Core\Cache\Exception
      */
@@ -101,8 +99,7 @@ public function setCache(\TYPO3\CMS\Core\Cache\Frontend\FrontendInterface $cache
      * assumed that the directory is below the TYPO3_DOCUMENT_ROOT. However, an
      * absolute path can be selected, too.
      *
-     * This method does not exist in FLOW3 anymore, but it is needed in
-     * TYPO3 v4 to enable a cache path outside of document root. The final
+     * This method enables to use a cache path outside of document root. The final
      * cache path is checked and created in createFinalCachDirectory(),
      * called by setCache() method, which is done _after_ the cacheDirectory
      * option was handled.
@@ -174,8 +171,7 @@ public function setCacheDirectory($cacheDirectory)
     }
 
     /**
-     * Create the final cache directory if it does not exist. This method
-     * exists in TYPO3 v4 only.
+     * Create the final cache directory if it does not exist.
      *
      * @param string $finalCacheDirectory Absolute path to final cache directory
      * @throws \TYPO3\CMS\Core\Cache\Exception If directory is not writable after creation
diff --git a/typo3/sysext/core/Classes/Cache/Backend/TaggableBackendInterface.php b/typo3/sysext/core/Classes/Cache/Backend/TaggableBackendInterface.php
index bca3cfc9b9d2..e800133a8f5c 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/TaggableBackendInterface.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/TaggableBackendInterface.php
@@ -1,15 +1,19 @@
 <?php
 namespace TYPO3\CMS\Core\Cache\Backend;
 
-/*                                                                        *
- * This script belongs to the FLOW3 framework.                            *
- *                                                                        *
- * It is free software; you can redistribute it and/or modify it under    *
- * the terms of the GNU Lesser General Public License, either version 3   *
- * of the License, or (at your option) any later version.                 *
- *                                                                        *
- * The TYPO3 project - inspiring people to share!                         *
- *                                                                        */
+/*
+ * This file is part of the TYPO3 CMS project.
+ *
+ * It is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, either version 2
+ * of the License, or any later version.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.txt file that was distributed with this source code.
+ *
+ * The TYPO3 project - inspiring people to share!
+ */
+
 /**
  * A contract for a cache backend which supports tagging.
  *
diff --git a/typo3/sysext/core/Classes/Cache/Backend/TransientMemoryBackend.php b/typo3/sysext/core/Classes/Cache/Backend/TransientMemoryBackend.php
index 8c482290cb21..e1199648cef6 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/TransientMemoryBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/TransientMemoryBackend.php
@@ -17,7 +17,6 @@
 /**
  * A caching backend which stores cache entries during one script run.
  *
- * This file is a backport from FLOW3
  * @api
  */
 class TransientMemoryBackend extends \TYPO3\CMS\Core\Cache\Backend\AbstractBackend implements TaggableBackendInterface, TransientBackendInterface
diff --git a/typo3/sysext/core/Classes/Cache/Backend/WincacheBackend.php b/typo3/sysext/core/Classes/Cache/Backend/WincacheBackend.php
index 11bb207bb75b..107dcf3e3aea 100644
--- a/typo3/sysext/core/Classes/Cache/Backend/WincacheBackend.php
+++ b/typo3/sysext/core/Classes/Cache/Backend/WincacheBackend.php
@@ -46,7 +46,7 @@ class WincacheBackend extends \TYPO3\CMS\Core\Cache\Backend\AbstractBackend impl
     /**
      * Constructs this backend
      *
-     * @param string $context FLOW3's application context
+     * @param string $context Unused, for backward compatibility only
      * @param array $options Configuration options
      * @throws \TYPO3\CMS\Core\Cache\Exception If wincache PHP extension is not loaded
      */
diff --git a/typo3/sysext/core/Classes/Cache/CacheManager.php b/typo3/sysext/core/Classes/Cache/CacheManager.php
index 3ce75523a589..7dc233a40fd3 100644
--- a/typo3/sysext/core/Classes/Cache/CacheManager.php
+++ b/typo3/sysext/core/Classes/Cache/CacheManager.php
@@ -29,7 +29,6 @@
 /**
  * The Cache Manager
  *
- * This file is a backport from FLOW3
  * @api
  */
 class CacheManager implements SingletonInterface
diff --git a/typo3/sysext/core/Classes/Cache/Exception.php b/typo3/sysext/core/Classes/Cache/Exception.php
index 1de47ed4e09c..d5a924d47ad9 100644
--- a/typo3/sysext/core/Classes/Cache/Exception.php
+++ b/typo3/sysext/core/Classes/Cache/Exception.php
@@ -17,8 +17,6 @@
 /**
  * A generic Cache exception
  *
- * This file is a backport from FLOW3
- *
  * @api
  */
 class Exception extends \Exception
diff --git a/typo3/sysext/core/Classes/Cache/Exception/DuplicateIdentifierException.php b/typo3/sysext/core/Classes/Cache/Exception/DuplicateIdentifierException.php
index 49ee54488e56..030ffecc3c5c 100644
--- a/typo3/sysext/core/Classes/Cache/Exception/DuplicateIdentifierException.php
+++ b/typo3/sysext/core/Classes/Cache/Exception/DuplicateIdentifierException.php
@@ -17,8 +17,6 @@
 /**
  * A "Duplicate Identifier" exception
  *
- * This file is a backport from FLOW3
- *
  * @api
  */
 class DuplicateIdentifierException extends \TYPO3\CMS\Core\Cache\Exception
diff --git a/typo3/sysext/core/Classes/Cache/Exception/InvalidBackendException.php b/typo3/sysext/core/Classes/Cache/Exception/InvalidBackendException.php
index ed5965f8787f..594c5f0a4257 100644
--- a/typo3/sysext/core/Classes/Cache/Exception/InvalidBackendException.php
+++ b/typo3/sysext/core/Classes/Cache/Exception/InvalidBackendException.php
@@ -17,8 +17,6 @@
 /**
  * An "Invalid Backend" exception
  *
- * This file is a backport from FLOW3
- *
  * @api
  */
 class InvalidBackendException extends \TYPO3\CMS\Core\Cache\Exception
diff --git a/typo3/sysext/core/Classes/Cache/Exception/InvalidCacheException.php b/typo3/sysext/core/Classes/Cache/Exception/InvalidCacheException.php
index 4b9b8b0a5b24..871cf05f360e 100644
--- a/typo3/sysext/core/Classes/Cache/Exception/InvalidCacheException.php
+++ b/typo3/sysext/core/Classes/Cache/Exception/InvalidCacheException.php
@@ -17,8 +17,6 @@
 /**
  * An "Invalid Cache" exception
  *
- * This file is a backport from FLOW3
- *
  * @api
  */
 class InvalidCacheException extends \TYPO3\CMS\Core\Cache\Exception
diff --git a/typo3/sysext/core/Classes/Cache/Exception/InvalidDataException.php b/typo3/sysext/core/Classes/Cache/Exception/InvalidDataException.php
index 9d7e3cc4c694..5877c0471490 100644
--- a/typo3/sysext/core/Classes/Cache/Exception/InvalidDataException.php
+++ b/typo3/sysext/core/Classes/Cache/Exception/InvalidDataException.php
@@ -17,8 +17,6 @@
 /**
  * An "Invalid Data" exception
  *
- * This file is a backport from FLOW3
- *
  * @api
  */
 class InvalidDataException extends \TYPO3\CMS\Core\Cache\Exception
diff --git a/typo3/sysext/core/Classes/Cache/Exception/NoSuchCacheException.php b/typo3/sysext/core/Classes/Cache/Exception/NoSuchCacheException.php
index 5e53153bde61..8af6da31d5df 100644
--- a/typo3/sysext/core/Classes/Cache/Exception/NoSuchCacheException.php
+++ b/typo3/sysext/core/Classes/Cache/Exception/NoSuchCacheException.php
@@ -17,8 +17,6 @@
 /**
  * A "No Such Cache" exception
  *
- * This file is a backport from FLOW3
- *
  * @api
  */
 class NoSuchCacheException extends \TYPO3\CMS\Core\Cache\Exception
diff --git a/typo3/sysext/core/Classes/Cache/Frontend/AbstractFrontend.php b/typo3/sysext/core/Classes/Cache/Frontend/AbstractFrontend.php
index 69e0fec771c4..b7223ab289bb 100644
--- a/typo3/sysext/core/Classes/Cache/Frontend/AbstractFrontend.php
+++ b/typo3/sysext/core/Classes/Cache/Frontend/AbstractFrontend.php
@@ -22,7 +22,6 @@
 /**
  * An abstract cache
  *
- * This file is a backport from FLOW3
  * @api
  */
 abstract class AbstractFrontend implements FrontendInterface
diff --git a/typo3/sysext/core/Classes/Cache/Frontend/PhpFrontend.php b/typo3/sysext/core/Classes/Cache/Frontend/PhpFrontend.php
index 8c2cd7e6780d..9baebfd54aba 100644
--- a/typo3/sysext/core/Classes/Cache/Frontend/PhpFrontend.php
+++ b/typo3/sysext/core/Classes/Cache/Frontend/PhpFrontend.php
@@ -20,7 +20,6 @@
 /**
  * A cache frontend tailored to PHP code.
  *
- * This file is a backport from FLOW3
  * @api
  */
 class PhpFrontend extends AbstractFrontend
diff --git a/typo3/sysext/core/Classes/Cache/Frontend/StringFrontend.php b/typo3/sysext/core/Classes/Cache/Frontend/StringFrontend.php
index 8d6803a11a59..db8e699896dd 100644
--- a/typo3/sysext/core/Classes/Cache/Frontend/StringFrontend.php
+++ b/typo3/sysext/core/Classes/Cache/Frontend/StringFrontend.php
@@ -20,7 +20,6 @@
 /**
  * A cache frontend for strings. Nothing else.
  *
- * This file is a backport from FLOW3
  * @api
  * @deprecated since TYPO3 v9, will be removed in TYPO3 v10 - use VariableFrontend instead.
  */
diff --git a/typo3/sysext/core/Classes/Database/PdoHelper.php b/typo3/sysext/core/Classes/Database/PdoHelper.php
index 5d9dc27516fc..35e1abf991fe 100644
--- a/typo3/sysext/core/Classes/Database/PdoHelper.php
+++ b/typo3/sysext/core/Classes/Database/PdoHelper.php
@@ -16,7 +16,6 @@
 
 /**
  * A helper class for handling PDO databases
- * Backport of FLOW3 class PdoHelper, last synced version: 3528
  */
 class PdoHelper
 {
diff --git a/typo3/sysext/core/Classes/Error/Exception.php b/typo3/sysext/core/Classes/Error/Exception.php
index 6ace1aa473eb..f88d877fdcb2 100644
--- a/typo3/sysext/core/Classes/Error/Exception.php
+++ b/typo3/sysext/core/Classes/Error/Exception.php
@@ -16,8 +16,6 @@
 
 /**
  * An exception which represents a PHP error.
- *
- * This file is a backport from FLOW3
  */
 class Exception extends \TYPO3\CMS\Core\Exception
 {
diff --git a/typo3/sysext/core/Classes/Localization/Locales.php b/typo3/sysext/core/Classes/Localization/Locales.php
index b328d77cadca..43bcc31111b3 100644
--- a/typo3/sysext/core/Classes/Localization/Locales.php
+++ b/typo3/sysext/core/Classes/Localization/Locales.php
@@ -88,7 +88,7 @@ class Locales implements \TYPO3\CMS\Core\SingletonInterface
     ];
 
     /**
-     * Reversed mapping with codes used by TYPO3 4.5 and below
+     * Reversed mapping for backward compatibility codes
      *
      * @var array
      */
@@ -116,7 +116,7 @@ class Locales implements \TYPO3\CMS\Core\SingletonInterface
     ];
 
     /**
-     * Mapping with codes used by TYPO3 4.5 and below
+     * Mapping for backward compatibility codes
      *
      * @var array
      */
diff --git a/typo3/sysext/core/Classes/Package/Exception/InvalidPackageKeyException.php b/typo3/sysext/core/Classes/Package/Exception/InvalidPackageKeyException.php
index 5f582d25d632..7d261642b4e1 100644
--- a/typo3/sysext/core/Classes/Package/Exception/InvalidPackageKeyException.php
+++ b/typo3/sysext/core/Classes/Package/Exception/InvalidPackageKeyException.php
@@ -16,7 +16,6 @@
 
 /**
  * An "Invalid Package Key" exception
- * Adapted from FLOW for TYPO3 CMS
  */
 class InvalidPackageKeyException extends \TYPO3\CMS\Core\Package\Exception
 {
diff --git a/typo3/sysext/core/Classes/Package/Exception/InvalidPackageManifestException.php b/typo3/sysext/core/Classes/Package/Exception/InvalidPackageManifestException.php
index 114f49d1966d..a69a4ec351eb 100644
--- a/typo3/sysext/core/Classes/Package/Exception/InvalidPackageManifestException.php
+++ b/typo3/sysext/core/Classes/Package/Exception/InvalidPackageManifestException.php
@@ -16,7 +16,6 @@
 
 /**
  * An "Invalid Package Manifest" exception
- * Adapted from FLOW for TYPO3 CMS
  */
 class InvalidPackageManifestException extends \TYPO3\CMS\Core\Package\Exception
 {
diff --git a/typo3/sysext/core/Classes/Package/Exception/InvalidPackagePathException.php b/typo3/sysext/core/Classes/Package/Exception/InvalidPackagePathException.php
index 128250f4e1b7..453f04bfae98 100644
--- a/typo3/sysext/core/Classes/Package/Exception/InvalidPackagePathException.php
+++ b/typo3/sysext/core/Classes/Package/Exception/InvalidPackagePathException.php
@@ -16,7 +16,6 @@
 
 /**
  * "Invalid Package Path" Exception
- * Adapted from FLOW for TYPO3 CMS
  */
 class InvalidPackagePathException extends \TYPO3\CMS\Core\Package\Exception
 {
diff --git a/typo3/sysext/core/Classes/Package/Exception/InvalidPackageStateException.php b/typo3/sysext/core/Classes/Package/Exception/InvalidPackageStateException.php
index f174c9abe88c..35569c6b2301 100644
--- a/typo3/sysext/core/Classes/Package/Exception/InvalidPackageStateException.php
+++ b/typo3/sysext/core/Classes/Package/Exception/InvalidPackageStateException.php
@@ -16,7 +16,6 @@
 
 /**
  * An "Invalid Package State" exception
- * Adapted from FLOW for TYPO3 CMS
  */
 class InvalidPackageStateException extends \TYPO3\CMS\Core\Package\Exception
 {
diff --git a/typo3/sysext/core/Classes/Package/Exception/MissingPackageManifestException.php b/typo3/sysext/core/Classes/Package/Exception/MissingPackageManifestException.php
index c0ee96c81cf4..2fc07d11e703 100644
--- a/typo3/sysext/core/Classes/Package/Exception/MissingPackageManifestException.php
+++ b/typo3/sysext/core/Classes/Package/Exception/MissingPackageManifestException.php
@@ -16,7 +16,6 @@
 
 /**
  * An "Invalid Package Key" exception
- * Adapted from FLOW for TYPO3 CMS
  */
 class MissingPackageManifestException extends \TYPO3\CMS\Core\Package\Exception
 {
diff --git a/typo3/sysext/core/Classes/Package/Exception/PackageStatesFileNotWritableException.php b/typo3/sysext/core/Classes/Package/Exception/PackageStatesFileNotWritableException.php
index 0fff25e290f6..4ccfba7e6e04 100644
--- a/typo3/sysext/core/Classes/Package/Exception/PackageStatesFileNotWritableException.php
+++ b/typo3/sysext/core/Classes/Package/Exception/PackageStatesFileNotWritableException.php
@@ -16,7 +16,6 @@
 
 /**
  * "Package states file not writable" Exception
- * Adapted from FLOW for TYPO3 CMS
  */
 class PackageStatesFileNotWritableException extends \TYPO3\CMS\Core\Package\Exception
 {
diff --git a/typo3/sysext/core/Classes/Package/Exception/ProtectedPackageKeyException.php b/typo3/sysext/core/Classes/Package/Exception/ProtectedPackageKeyException.php
index e535b5ad9817..0ebf19e0ac69 100644
--- a/typo3/sysext/core/Classes/Package/Exception/ProtectedPackageKeyException.php
+++ b/typo3/sysext/core/Classes/Package/Exception/ProtectedPackageKeyException.php
@@ -16,7 +16,6 @@
 
 /**
  * A "Protected Package Key" exception
- * Adapted from FLOW for TYPO3 CMS
  */
 class ProtectedPackageKeyException extends \TYPO3\CMS\Core\Package\Exception
 {
diff --git a/typo3/sysext/core/Classes/Package/Exception/UnknownPackageException.php b/typo3/sysext/core/Classes/Package/Exception/UnknownPackageException.php
index 1548f4a9c7d1..8e38b42b5c14 100644
--- a/typo3/sysext/core/Classes/Package/Exception/UnknownPackageException.php
+++ b/typo3/sysext/core/Classes/Package/Exception/UnknownPackageException.php
@@ -16,7 +16,6 @@
 
 /**
  * "Unknown Package" Exception
- * Adapted from FLOW for TYPO3 CMS
  */
 class UnknownPackageException extends \TYPO3\CMS\Core\Package\Exception
 {
diff --git a/typo3/sysext/core/Classes/Package/MetaData.php b/typo3/sysext/core/Classes/Package/MetaData.php
index 034333a01943..442e06157f32 100644
--- a/typo3/sysext/core/Classes/Package/MetaData.php
+++ b/typo3/sysext/core/Classes/Package/MetaData.php
@@ -16,7 +16,6 @@
 
 /**
  * The default TYPO3 Package MetaData implementation
- * Adapted from FLOW for TYPO3 CMS
  */
 class MetaData
 {
diff --git a/typo3/sysext/core/Classes/Package/MetaData/PackageConstraint.php b/typo3/sysext/core/Classes/Package/MetaData/PackageConstraint.php
index 9a5a34cc66c7..3e72f567ab07 100644
--- a/typo3/sysext/core/Classes/Package/MetaData/PackageConstraint.php
+++ b/typo3/sysext/core/Classes/Package/MetaData/PackageConstraint.php
@@ -16,7 +16,6 @@
 
 /**
  * Package constraint meta model
- * Adapted from FLOW for TYPO3 CMS
  */
 class PackageConstraint
 {
diff --git a/typo3/sysext/core/Classes/Package/Package.php b/typo3/sysext/core/Classes/Package/Package.php
index b0d7ef920113..e604f62f7fbc 100644
--- a/typo3/sysext/core/Classes/Package/Package.php
+++ b/typo3/sysext/core/Classes/Package/Package.php
@@ -16,7 +16,6 @@
 
 /**
  * A Package representing the details of an extension and/or a composer package
- * Adapted from FLOW for TYPO3 CMS
  */
 class Package implements PackageInterface
 {
diff --git a/typo3/sysext/core/Classes/Package/PackageInterface.php b/typo3/sysext/core/Classes/Package/PackageInterface.php
index 7d8987b7dcca..e96fc37297a3 100644
--- a/typo3/sysext/core/Classes/Package/PackageInterface.php
+++ b/typo3/sysext/core/Classes/Package/PackageInterface.php
@@ -16,7 +16,6 @@
 
 /**
  * Interface for a TYPO3 Package class
- * Adapted from FLOW for TYPO3 CMS
  */
 interface PackageInterface
 {
diff --git a/typo3/sysext/core/Classes/Package/PackageManager.php b/typo3/sysext/core/Classes/Package/PackageManager.php
index c48a3774f16a..64b4eab331f7 100644
--- a/typo3/sysext/core/Classes/Package/PackageManager.php
+++ b/typo3/sysext/core/Classes/Package/PackageManager.php
@@ -28,7 +28,6 @@
 
 /**
  * The default TYPO3 Package Manager
- * Adapted from FLOW for TYPO3 CMS
  */
 class PackageManager implements \TYPO3\CMS\Core\SingletonInterface
 {
diff --git a/typo3/sysext/core/Classes/Page/PageRenderer.php b/typo3/sysext/core/Classes/Page/PageRenderer.php
index 543bdf82370f..41d9792dfeb9 100644
--- a/typo3/sysext/core/Classes/Page/PageRenderer.php
+++ b/typo3/sysext/core/Classes/Page/PageRenderer.php
@@ -26,7 +26,7 @@
 use TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController;
 
 /**
- * TYPO3 pageRender class (new in TYPO3 4.3.0)
+ * TYPO3 pageRender class
  * This class render the HTML of a webpage, usable for BE and FE
  */
 class PageRenderer implements \TYPO3\CMS\Core\SingletonInterface
diff --git a/typo3/sysext/core/Tests/Unit/Cache/Backend/ApcBackendTest.php b/typo3/sysext/core/Tests/Unit/Cache/Backend/ApcBackendTest.php
index 6ca51a33de63..1dc21226ac23 100644
--- a/typo3/sysext/core/Tests/Unit/Cache/Backend/ApcBackendTest.php
+++ b/typo3/sysext/core/Tests/Unit/Cache/Backend/ApcBackendTest.php
@@ -21,8 +21,6 @@
  *
  * NOTE: If you want to execute these tests you need to enable apc in
  * cli context (apc.enable_cli = 1)
- *
- * This file is a backport from FLOW3
  */
 class ApcBackendTest extends \TYPO3\TestingFramework\Core\Unit\UnitTestCase
 {
diff --git a/typo3/sysext/core/Tests/Unit/Cache/Backend/FileBackendTest.php b/typo3/sysext/core/Tests/Unit/Cache/Backend/FileBackendTest.php
index f956025f87a3..928355af4c72 100644
--- a/typo3/sysext/core/Tests/Unit/Cache/Backend/FileBackendTest.php
+++ b/typo3/sysext/core/Tests/Unit/Cache/Backend/FileBackendTest.php
@@ -21,8 +21,6 @@
 
 /**
  * Testcase for the File cache backend
- *
- * This file is a backport from FLOW3
  */
 class FileBackendTest extends \TYPO3\TestingFramework\Core\Unit\UnitTestCase
 {
diff --git a/typo3/sysext/core/Tests/Unit/Cache/Backend/MockBackend.php b/typo3/sysext/core/Tests/Unit/Cache/Backend/MockBackend.php
index 9b19fbb3241e..03649d4e4c35 100644
--- a/typo3/sysext/core/Tests/Unit/Cache/Backend/MockBackend.php
+++ b/typo3/sysext/core/Tests/Unit/Cache/Backend/MockBackend.php
@@ -17,8 +17,6 @@
 /**
  * A caching backend which forgets everything immediately
  * Used in FactoryTest
- *
- * This file is a backport from FLOW3
  */
 class MockBackend extends \TYPO3\CMS\Core\Cache\Backend\NullBackend
 {
diff --git a/typo3/sysext/core/Tests/Unit/Cache/Backend/TransientMemoryBackendTest.php b/typo3/sysext/core/Tests/Unit/Cache/Backend/TransientMemoryBackendTest.php
index 803bcd29e6ac..146e4df55cab 100644
--- a/typo3/sysext/core/Tests/Unit/Cache/Backend/TransientMemoryBackendTest.php
+++ b/typo3/sysext/core/Tests/Unit/Cache/Backend/TransientMemoryBackendTest.php
@@ -16,8 +16,6 @@
 
 /**
  * Testcase for the TransientMemory cache backend
- *
- * This file is a backport from FLOW3
  */
 class TransientMemoryBackendTest extends \TYPO3\TestingFramework\Core\Unit\UnitTestCase
 {
diff --git a/typo3/sysext/core/Tests/Unit/Cache/CacheManagerTest.php b/typo3/sysext/core/Tests/Unit/Cache/CacheManagerTest.php
index c82a2f289202..ab4fb930b4fa 100644
--- a/typo3/sysext/core/Tests/Unit/Cache/CacheManagerTest.php
+++ b/typo3/sysext/core/Tests/Unit/Cache/CacheManagerTest.php
@@ -32,8 +32,6 @@
 
 /**
  * Testcase for the TYPO3\CMS\Core\Cache\CacheManager
- *
- * This file is a backport from FLOW3
  */
 class CacheManagerTest extends \TYPO3\TestingFramework\Core\Unit\UnitTestCase
 {
diff --git a/typo3/sysext/core/Tests/Unit/Cache/Fixtures/BackendConfigurationOptionFixture.php b/typo3/sysext/core/Tests/Unit/Cache/Fixtures/BackendConfigurationOptionFixture.php
index feb4cffce0ed..65aec0e3302d 100644
--- a/typo3/sysext/core/Tests/Unit/Cache/Fixtures/BackendConfigurationOptionFixture.php
+++ b/typo3/sysext/core/Tests/Unit/Cache/Fixtures/BackendConfigurationOptionFixture.php
@@ -22,7 +22,7 @@ class BackendConfigurationOptionFixture extends BackendFixture
     /**
      * Test if constructor receives backend options
      *
-     * @param string $context FLOW3's application context
+     * @param string $context Unused, for backward compatibility only
      * @param array $options Configuration options - depends on the actual backend
      */
     public function __construct($context, array $options = [])
diff --git a/typo3/sysext/core/Tests/Unit/Cache/Frontend/AbstractFrontendTest.php b/typo3/sysext/core/Tests/Unit/Cache/Frontend/AbstractFrontendTest.php
index 1ec7fae0e281..7bfa93a24b4d 100644
--- a/typo3/sysext/core/Tests/Unit/Cache/Frontend/AbstractFrontendTest.php
+++ b/typo3/sysext/core/Tests/Unit/Cache/Frontend/AbstractFrontendTest.php
@@ -16,8 +16,6 @@
 
 /**
  * Testcase for the abstract cache frontend
- *
- * This file is a backport from FLOW3
  */
 class AbstractFrontendTest extends \TYPO3\TestingFramework\Core\Unit\UnitTestCase
 {
diff --git a/typo3/sysext/core/Tests/Unit/Cache/Frontend/PhpFrontendTest.php b/typo3/sysext/core/Tests/Unit/Cache/Frontend/PhpFrontendTest.php
index 73f45868b549..d1e7f961d4b4 100644
--- a/typo3/sysext/core/Tests/Unit/Cache/Frontend/PhpFrontendTest.php
+++ b/typo3/sysext/core/Tests/Unit/Cache/Frontend/PhpFrontendTest.php
@@ -17,8 +17,6 @@
 
 /**
  * Testcase for the PHP source code cache frontend
- *
- * This file is a backport from FLOW3
  */
 class PhpFrontendTest extends \TYPO3\TestingFramework\Core\Unit\UnitTestCase
 {
diff --git a/typo3/sysext/core/Tests/UnitDeprecated/Cache/Frontend/StringFrontendTest.php b/typo3/sysext/core/Tests/UnitDeprecated/Cache/Frontend/StringFrontendTest.php
index 7cd7b2113dee..c26fe9184f98 100644
--- a/typo3/sysext/core/Tests/UnitDeprecated/Cache/Frontend/StringFrontendTest.php
+++ b/typo3/sysext/core/Tests/UnitDeprecated/Cache/Frontend/StringFrontendTest.php
@@ -17,8 +17,6 @@
 
 /**
  * Testcase for the string cache frontend
- *
- * This file is a backport from FLOW3
  */
 class StringFrontendTest extends \TYPO3\TestingFramework\Core\Unit\UnitTestCase
 {
diff --git a/typo3/sysext/extbase/Classes/Core/Bootstrap.php b/typo3/sysext/extbase/Classes/Core/Bootstrap.php
index e56d73aebae9..98b68c43d4a4 100644
--- a/typo3/sysext/extbase/Classes/Core/Bootstrap.php
+++ b/typo3/sysext/extbase/Classes/Core/Bootstrap.php
@@ -21,7 +21,7 @@
 
 /**
  * Creates a request an dispatches it to the controller which was specified
- * by TS Setup, flexForm and returns the content to the v4 framework.
+ * by TS Setup, flexForm and returns the content.
  *
  * This class is the main entry point for extbase extensions.
  */
diff --git a/typo3/sysext/extbase/Classes/DomainObject/AbstractDomainObject.php b/typo3/sysext/extbase/Classes/DomainObject/AbstractDomainObject.php
index ecb843d660a0..ec33d0e01c3a 100644
--- a/typo3/sysext/extbase/Classes/DomainObject/AbstractDomainObject.php
+++ b/typo3/sysext/extbase/Classes/DomainObject/AbstractDomainObject.php
@@ -29,12 +29,12 @@ abstract class AbstractDomainObject implements DomainObjectInterface, \TYPO3\CMS
     protected $uid;
 
     /**
-     * @var int The uid of the localized record. In TYPO3 v4.x the property "uid" holds the uid of the record in default language (the translationOrigin).
+     * @var int The uid of the localized record. Holds the uid of the record in default language (the translationOrigin).
      */
     protected $_localizedUid;
 
     /**
-     * @var int The uid of the language of the object. In TYPO3 v4.x this is the uid of the language record in the table sys_language.
+     * @var int The uid of the language of the object. This is the uid of the language record in the table sys_language.
      */
     protected $_languageUid;
 
diff --git a/typo3/sysext/fluid/Classes/ViewHelpers/FormViewHelper.php b/typo3/sysext/fluid/Classes/ViewHelpers/FormViewHelper.php
index 10d7b46c9b87..349b3564d3ab 100644
--- a/typo3/sysext/fluid/Classes/ViewHelpers/FormViewHelper.php
+++ b/typo3/sysext/fluid/Classes/ViewHelpers/FormViewHelper.php
@@ -389,7 +389,6 @@ protected function renderRequestHashField()
         $formFieldNames = $this->viewHelperVariableContainer->get(\TYPO3\CMS\Fluid\ViewHelpers\FormViewHelper::class, 'formFieldNames');
         $this->postProcessUriArgumentsForRequestHash($this->formActionUriArguments, $formFieldNames);
         $requestHash = $this->requestHashService->generateRequestHash($formFieldNames, $this->getFieldNamePrefix());
-        // in v4, we need to prefix __hmac as well to make it show up in the request object.
         return '<input type="hidden" name="' . $this->prefixFieldName('__hmac') . '" value="' . htmlspecialchars($requestHash) . '" />';
     }