Core Platform Team/Initiative/Stability annotations/base classes

Extensible Base Classes
includes/Rest/Handler.php includes/Rest/SimpleHandler.php includes/Revision/SlotRoleHandler.php includes/actions/Action.php includes/actions/CachedAction.php includes/actions/FormAction.php includes/actions/FormlessAction.php includes/api/ApiBase.php includes/api/ApiQueryBase.php includes/api/ApiQueryGeneratorBase.php includes/api/ApiQueryRevisionsBase.php includes/auth/AbstractAuthenticationProvider.php includes/auth/AbstractPasswordPrimaryAuthenticationProvider.php includes/auth/AbstractPreAuthenticationProvider.php includes/auth/AbstractPrimaryAuthenticationProvider.php includes/auth/AbstractSecondaryAuthenticationProvider.php includes/auth/AuthenticationRequest.php includes/changetags/ChangeTagsList.php includes/content/AbstractContent.php includes/content/CodeContentHandler.php includes/content/ContentHandler.php includes/context/ContextSource.php includes/dao/DBAccessBase.php includes/deferred/DataUpdate.php includes/filerepo/file/File.php includes/jobqueue/Job.php includes/libs/GenericArrayObject.php includes/libs/ParamValidator/TypeDef.php (marked @unstable as well!) includes/libs/ParamValidator/TypeDef/NumericDef.php includes/libs/eventrelayer/EventRelayer.php includes/libs/filebackend/FileBackend.php includes/libs/filebackend/FileBackendStore.php includes/libs/filebackend/filejournal/FileJournal.php includes/libs/filebackend/fileophandle/FileBackendStoreOpHandle.php includes/libs/iterators/IteratorDecorator.php includes/libs/lockmanager/DBLockManager.php includes/libs/lockmanager/LockManager.php includes/libs/lockmanager/QuorumLockManager.php includes/libs/objectcache/BagOStuff.php includes/libs/rdbms/database/Database.php includes/logging/LogEntryBase.php includes/logging/LogFormatter.php includes/media/ImageHandler.php includes/media/MediaHandler.php includes/media/MediaTransformOutput.php includes/media/TransformationalImageHandler.php includes/pager/AlphabeticPager.php includes/pager/IndexPager.php includes/pager/RangeChronologicalPager.php includes/pager/ReverseChronologicalPager.php includes/pager/TablePager.php includes/resourceloader/ResourceLoaderModule.php includes/search/BaseSearchResultSet.php includes/search/PrefixSearch.php includes/search/SearchDatabase.php includes/search/SearchEngine.php includes/search/SearchIndexFieldDefinition.php includes/session/ImmutableSessionProviderWithCookie.php includes/session/SessionProvider.php includes/skins/BaseTemplate.php includes/skins/QuickTemplate.php includes/skins/Skin.php includes/skins/SkinTemplate.php includes/specialpage/ImageQueryPage.php includes/specialpage/LoginSignupSpecialPage.php includes/specialpage/PageQueryPage.php includes/specialpage/QueryPage.php includes/specialpage/RedirectSpecialArticle.php includes/specialpage/RedirectSpecialPage.php includes/specialpage/SpecialPage.php includes/specialpage/SpecialRedirectToSpecial.php includes/specialpage/SpecialRedirectWithAction.php includes/specialpage/UnlistedSpecialPage.php includes/specialpage/WantedQueryPage.php includes/specials/SpecialCachedPage.php includes/upload/UploadBase.php maintenance/includes/Maintenance.php tests/phpunit/MediaWikiIntegrationTestCase.php tests/phpunit/MediaWikiUnitTestCase.php

...and the entire HTMLFormField hierarchy?!

Problematic classes that are subclassed by extensions
OldChangesList - AbuseFilter TableDiffFormatter - AbuseFilter