path: root/RELEASE-NOTES-1.37

= MediaWiki 1.37 =

== MediaWiki 1.37.1 ==

This is a security and maintenance release of the MediaWiki 1.37 branch.

=== Changes since MediaWiki 1.37.0 ===
* (T296112) Allow inserting new sections named '0'.
* Fix path for ZhConversion.php.
* nukeNS: don't run purgeRedundantText() after every change.
* (T286779, T297031) installer: Fix Postgres mistakes in using changeField
  method.
* (T225888) RollbackAction: fix missing pagetitle.
* (T297322, CVE-2021-44858, CVE-2021-44857) SECURITY: Fix permissions checks in
  undo actions.
* (T297574, CVE-2021-45038) SECURITY: Fix permissions check in action=rollback.
* (T34716, T297416) SECURITY: Require 'read' right for most actions.
* (T271037, CVE-2021-44856) SECURITY: Fix use of EditFilterMergedContent hook
  when changing content model.

== MediaWiki 1.37.0 ==

=== Changes since MediaWiki 1.37.0-rc.2 ===
* Remove justinrainbow/json-schema from vendor.
* Updated pear/mail_mime from 1.10.9 to 1.10.11.
* Update deprecated Guzzle Psr7 function calls.
* (T281972) UserIdentityValue: Correct @since tags.
* Updated wikimedia/parsoid from v0.14.0-a19 to v0.14.0.
* Localisation updates.
* Tweak error message for missing composer dependencies.

== MediaWiki 1.37.0-rc.2 ==

=== Changes since MediaWiki 1.37.0-rc.1 ===
* (T295173) Re-add wikimedia/normalized-exception to vendor.
* Remove wikimedia/testing-access-wrapper, psr/simple-cache, psr/http-factory
  from vendor.
* (T295191) ApiQuerySiteinfo: Fix "rightsinfo"/"url" when $wgRightsPage is set.
* (T212428) Allow populateContentTables to continue when there are bad blobs.

== MediaWiki 1.37.0-rc.1 ==

=== Changes since MediaWiki 1.37.0-rc.0 ===
* (T294043) checkStorage: pass no parameters to WikiRevision::getContent().
* (T292763, CVE-2021-44856) SECURITY: Do not cache private wiki completion
  results.
* (T293783) ApiQueryImageInfo: don't show empty comments as deleted.
* (T294316) Revert "Mark ApiClientLogin/ApiLogin as requiring write mode".
* (T294796) JobQueueRedis: Replace deprecated zSize with zCard.
* Remove duplicate settings from DefaultSettings.
* (T278037) NoLocalSettings: Pass an EmptyBagOStuff to TemplateParser.

== MediaWiki 1.37.0-rc.0 ==

== Upgrading notes for 1.37 ==
Don't forget to always back up your database before upgrading!

See the file UPGRADE for more detailed per-version upgrade instructions from the
oldest supported upgrading version, MediaWiki 1.27.

Some specific notes for MediaWiki 1.37 upgrades are below:
* (T280806) Deprecated methods of fetching API tokens have been removed. This
  may cause older bots and scripts to fail. Most queries are trivially
  updateable to using new methods. See the Action API changes section below
  for more information.

For notes on 1.36.x and older releases, see HISTORY.

=== Configuration changes for system administrators in 1.37 ===
* (T242768) The PasswordCannotMatchUsername password policy has been removed,
  please use PasswordCannotBeSubstringInUsername instead. If you have not
  customised your password policies, there will be nothing to do here.

==== New configuration ====
* $wgBrowserFormatDetection - This setting allows the enabling or disabling
  of automatic detection of possible phone numbers in a webpage in iOS Safari.
* $wgParserEnableLegacyMediaDOM - This setting defaults to true, and enables
  the legacy media HTML structure in the output from the Parser.  The
  alternative modern HTML structure for media is described at
  https://www.mediawiki.org/wiki/Parsing/Media_structure
  In a future release of MediaWiki this option will default to false,
  so it's a good idea to test this setting on your wiki early and report
  any issues.

==== Changed configuration ====
* $wgContentHandlerTextFallback - This migration setting, which defines how to
  react if a plain text version of a non-text Content object is requested using
  ContentHandler::getContentText(), is deprecated.
* $wgActions – This setting lets sysadmins over-ride which actions can be used.
  It has been re-worked to support injecting dependencies into Action sub-
  classes as part of wider work on dependency injection. Previously, $wgActions
  was an array where the keys were the names of actions, and the values had the
  following impacts (for a given key 'Foo'):
  - `true`: use the class 'FooAction' unless for a specific page
    WikiPage::getActionOverrides() wants to override that action
  - a string: use the class with that name, and do not allow over-riding on a
    per-page basis
  - `false`: the action is disabled
  - a callable: use the Action instance returned by invoking that callback, and
    do not allow overriding on a per-page basis
  - an object: use that specific Action instance, and do not allow overr-iding
    on a per-page basis.
  As part of T253078, values can now be arrays that are not callables, which are
  treated as ObjectFactory specs, allowing for services to be injected.
  Additionally, the distinction between values that allow per-page overrides and
  those that do not was removed - all actions can now be overridden on a per-
  page basis using WikiPage::getActionOverrides().
* $wgShellboxUrl – This setting, new in 1.36 to configure the novel Shellbox
  encapsulation system, is now deprecated; use $wgShellboxUrls as a mapping of
  service => URL instead.
* $wgIncludejQueryMigrate – This setting, introduced in 1.29 to on whether to
  provide a migration layer for jQuery, has now switched its default value from
  true to false. This may break gadgets that depended on methods that were
  removed in jQuery 3 in 2017. See T280944 for more information.
* A number of settings have been renamed. The former configuration variable
  names are deprecated, but will be used as the fall back if they are still set,
  and remain temporarily available for extensions which might try to read them:
  - $wgFileBlacklist is now $wgProhibitedFileExtensions
  - $wgMimeTypeBlacklist is now $wgMimeTypeExclusions
  - $wgEnableUserEmailBlacklist is now $wgEnableUserEmailMuteList
  - $wgShortPagesNamespaceBlacklist is now $wgShortPagesNamespaceExclusions
* $wgMimeTypeExclusions - As well as being renamed, this configuration array now
  also prohibits the RFC 4329 form of JavaScript, 'application/javascript', as
  well as previous MIME types.
* $wgFragmentMode - This setting, which determines the encoding of section IDs,
  has now switched its default value from legacy-first to html5-first: both the
  HTML5 anchor and the legacy percent-encoding-style anchor will still be
  generated for section titles, but references to them will use the HTML5
  version, resulting in human-readable fragments.

==== Removed configuration ====
* $wgLegacyJavaScriptGlobals, deprecated in 1.36.
* (T274695) $wgAjaxEditStash, deprecated in 1.36.
* $wgShowDBErrorBacktrace, deprecated and non-functional since 1.32.
* $wgShowSQLErrors, deprecated and non-functional since 1.32.
* $wgLangObjCacheSize, without deprecation; the LanguageFactory service now
  always retains at most 10 objects in its LRU-cache.
* $wgDjvuToXML, without deprecation; the tool it enables is obsolete and
  abandoned upstream. Use $wgDjvuDump to use that tool instead.

=== New user-facing features in 1.37 ===
* (T161934) MediaWiki now supports JPEG2000 files, to a limited extent.

=== External library changes in 1.37 ===

==== New external libraries ====
* Added symfony/polyfill-php80 1.23.1.
* Added whatwg-fetch 3.6.2.
* Added wikimedia/normalized-exception 1.0.1.

==== Changed external libraries ====
* Updated OOjs from v5.0.0 to v6.0.0
* Updated OOjs-Router from v0.2.0 to v0.3.0
* Updated OOUI from v0.41.3 to v0.42.0
* Updated WVUI from v0.1.0 to v0.3.0
* Updated cssjanus/cssjanus from v1.3.0 to v2.1.0.
* Updated pear/mail_mime from 1.10.9 to 1.10.11.
* Updated psr/container from v1.0.0 to v1.1.1.
* Updated wikimedia/minify from v2.2.2 to v2.2.4.
* Updated wikimedia/object-factory from v3.0.0 to v3.0.2.
* Updated wikimedia/parsoid from v0.13.1 to v0.14.0.
* Updated wikimedia/relpath from v2.1.1 to v3.0.0.
* Updated wikimedia/remex-html from v2.3.1 to v2.3.2.
* Updated wikimedia/shellbox from v1.0.4 to v2.0.0.
* Updated wikimedia/wait-condition-loop from v2.0.1 to v2.0.2.
* Updated zordius/lightncandy from v1.2.5 to v1.2.6.

===== Changed development-only external libraries =====
* Updated qunit from 2.10.0 to 2.16.0.

==== Removed external libraries ====
* The pimple/pimple development-only library has been removed.

=== Action API changes in 1.37 ===
* (T280806) The API methods for fetching tokens which were deprecated in
  MediaWiki 1.24 have been removed. action=query&meta=tokens&type= should be
  used instead. Please note some token types no longer exist, and you should
  just use type=csrf for those instead.
  - action=query&prop=info&intoken ->
      action=query&meta=tokens&type=csrf
  - action=tokens&type= ->
      action=query&meta=tokens&type=
  - action=query&list=recentchanges&rctoken ->
      action=query&meta=tokens&type=csrf
  - action=query&prop=revisions&rvtoken=rollback ->
      action=query&meta=tokens&type=rollback
  - action=query&meta=userinfo&uiprop=preferencestoken ->
      action=query&meta=tokens&type=csrf
  - action=query&list=users&ustoken=userrights ->
      action=query&meta=tokens&type=userrights

=== Languages updated in 1.37 ===
MediaWiki supports over 350 languages. Many localisations are updated regularly.
Below only new and removed languages are listed, as well as changes to languages
because of Phabricator reports.

* (T280435) LRM and RLM characters were removed from names of languages with
  parentheses in Names.php
* (T283422) Add namespace name translations and change the autonym of
  the Kinyarwanda language to "Ikinyarwanda".
* (T283423) Change the autonym of the Lombard language from "lumbaart"
  to "lombard".
* (T279619) Added language support for Dagbani (dag).
* (T282085) Added language support for Malay in Arabic (Jawi) script (ms-arab).
* (T283053) Added language support for Ojibwe (ojb).
* (T283480) Added language support for Wallisian (wls, Fakaʻuvea).
* (T284002) Added language support for Paiwan (pwn).
* (T284044) Added language support for Carpathian Romani (rmc).
* (T286460) Added language support for Gun (guw, Gungbe).
* (T287345) Added language support for Baoulé (bci).
* (T290126) Added language support for Kildin Sami (sjd).
* (T290408) Added language support for Pite Sami (sje).
* (T25216) Started the renaming of the language code for Norman from nrm to
  nrf.

=== Breaking changes in 1.37 ===
* The Revision class, emitting deprecation warnings since 1.35, was removed
  entirely. As part of this, the following hooks that included a Revision object
  were removed:
    - ArticleRevisionUndeleted - use RevisionUndeleted
    - ArticleRollbackComplete - use RollbackComplete
    - DiffRevisionTools - use DiffTools
    - DiffViewHeader - use DifferenceEngineViewHeader
    - HistoryRevisionTools - use HistoryTools
    - NewRevisionFromEditComplete - use RevisionFromEditComplete
    - PageContentInsertComplete - use PageSaveComplete
    - PageContentSaveComplete - use PageSaveComplete
    - ParserFetchTemplate - use BeforeParserFetchTemplateRevisionRecord
    - RevisionInsertComplete - use RevisionRecordInserted
    - TitleMoveComplete - use PageMoveComplete
    - TitleMoveCompleting - use PageMoveCompleting
    - UndeleteShowRevision - no replacement
    - UserRetrieveNewTalks - no replacement
  … the following methods and variables have been removed:
    - Article::$mRevision
    - Article::getRevisionFetched()
    - ContribsPager::tryToCreateValidRevision()
    - EditPage::$mBaseRevision
    - EditPage::getBaseRevision()
    - LinksUpdate::getRevision()
    - LinksUpdate::setRevision()
    - PageArchive::getArchivedRevision()
    - PageArchive::getPreviousRevision()
    - PageArchive::getRevision()
    - Parser::$mRevisionObject
    - Parser::fetchCurrentRevisionOfTitle()
    - Parser::getRevisionObject()
    - Parser::statelessFetchRevision()
    - ParserOptions::getCurrentRevisionCallback()
    - ParserOptions::setCurrentRevisionCallback()
    - Title::countAuthorsBetween()
    - Title::getFirstRevision()
    - User::getNewMessageLinks()
    - User::getNewMessageRevisionId()
    - User::setNewtalk()
    - WikiPage::getOldestRevision()
    - WikiPage::getRevision()
    - WikiPage::getUndoContent()
    - WikiPage::updateIfNewerOn()
  … and the following methods no longer accept Revision objects as parameters:
    - CategoryMembershipChange::__construct()
    - ContentHandler::getUndoContent()
    - DerivedPageDataUpdater::prepareUpdate()
    - DifferenceEngine::getRevisionHeader()
    - Linker::buildRollbackLink()
    - Linker::generateRollback()
    - Linker::getRevDeleteLink()
    - Linker::getRollbackEditCount()
    - Linker::revComment()
    - Linker::revUserLink()
    - Linker::revUserTools()
    - WikiPage::doDeleteUpdates()
    - WikiPage::doEditUpdates()
    - WikiPage::hasDifferencesOutsideMainSlot()
    - WikiPage::onArticleEdit()
    - WikiPage::prepareContentForEdit()
    - WikiPage::updateRevisionOn()
  The following methods return arrays that formerly included a 'revision'
  key that would emit deprecation warnings when accessed and return a
  Revision object. The Revision object has been removed from the arrays,
  and the 'revision-record' key should be used to get the relevant
  RevisionRecord instead:
    - PageUpdater::doCreate()
    - PageUpdater::doModify()
    - Parser::statelessFetchTemplate()
    - WikiPage::doEditContent()
  Finally, the ParserOptions `templateCallback` option is a callback that is
  called in Parser::fetchTemplateAndTitle() and should return an array - the
  'revision' key to that array used to be a Revision object and was used if
  no 'revision-record' was returned - is now ignored.
* Previously, the classes RevisionTestModifyableContent and
  RevisionTestModifyableContentHandler were loaded for use in tests, but were
  only used within the tests for the since-removed Revision class. This content
  and content handler class were removed without deprecation.
* WANObjectCache::HOLDOFF_NONE, deprecated since 1.35, was removed. Use
  WANObjectCache::HOLDOFF_TTL_NONE instead.
* Calling ResourceLoader::makeVersionQuery() without $modules parameter,
  deprecated since MediaWiki 1.34, is no longer supported.
* LocalFile::recordUpload2(), deprecated since 1.35, was removed.
* The following methods and fields in the Language class, deprecated since 1.35,
  have been removed:
   - ::classFromCode()
   - ::clearCaches()
   - ::convertTitle()
   - ::findVariantLink()
   - ::$mConverter
   - ::updateConversionTable()
* The following methods in the Parser class have been removed after having been
  deprecated in 1.35:
   - fetchTemplate()
   - Title()
* (T273354) When an edit is prevented by an 'EditFilterMergedContent' hook
  handler without changing the status, the edit form will now be displayed.
* User::clearNotification() which had been deprecated in 1.35 has been removed.
  Use WatchlistManager::clearTitleUserNotification() instead.
* User::getNewtalk() which had been deprecated in 1.35 has been removed. Use
  TalkPageNotificationManager::userHasNewMessages() instead.
* The Autopromote class, deprecated since 1.35, was removed. Use
  UserGroupManager instead.
* The CachedAction, SpecialCachedPage, CacheHelper, and ICacheHelper classes,
  all emitting deprecation warnings since 1.36, have been removed.
* The hooks BeforeHttpsRedirect, CanIPUseHTTPS and UserRequiresHTTPS, deprecated
  in 1.35, were removed.
* The TitleArrayFromResult hook, deprecated in 1.36, was removed.
* The deprecated "es6-promise" alias ResourceLoader module has been removed. Use
  the "es6-polyfills" module directly intead.
* The deprecated "mediawiki.legacy.protect" ResourceLoader module, deprecated
  since 1.36, has been removed. Use "mediawiki.action.protect" instead.
* The JavaScript alias $j for references to jQuery, deprecated since 1.23, has
  been removed. Use $ instead.
* The AuthenticationProvider interface and the SessionProvider class no longer
  extend the PSR LoggerAwareInterface concept, so they can't be typehinted as
  LoggerAwareInterface.
* User::getGrantName(), emitting deprecation warnings since 1.36, has been
  removed. Use MWGrants::grantName() instead.
* The following ApiBase methods, deprecated since 1.35, have been removed:
  - ApiBase::explodeMultiValue
  - ApiBase::parseMultiValue
  - ApiBase::validateLimit
  - ApiBase::validateTimestamp
* The User::idCacheByName() public static field was removed without deprecation.
  Instead of using it, get a UserIdentity by name from the UserIdentityLookup
  service.
* IDatabase::upsert() and IDatabase::replace() now only accept a single unique
  key. Previously, a warning was issued if there were multiple unique keys
  provided.
* The MediaWiki:Autoblock_whitelist block exemption control was moved in 1.36 to
  MediaWiki:Block-autoblock-exemptionlist. The backward-compatibility of reading
  the old MediaWiki:Autoblock_whitelist page has now been dropped.
* The following overridable methods in File hierarchy have changed signatures:
  - File::deleteFile() - now accepts UserIdentity instead of User
  - File::getDescription() - now accepts Authority instead of User
  - File::userCan() - now accepts Authority instead of User
  - LocalFile::deleteOldFile() - now accepts UserIdentity instead of User
* The following global methods, each deprecated since 1.36, have been removed:
  - wfAppendToArrayIfNotDefault()
  - wfAcceptToPrefs()
  - wfConfiguredReadOnlyReason()
  - wfDebugMem()
  - wfGetPrecompiledData()
  - wfNegotiateType()
* The following deprecated methods of the Title class have been removed:
  - ::nameOf(), deprecated in 1.36
  - ::getPreviousRevisionID(), deprecated in 1.34
  - ::getNextRevisionID(), deprecated in 1.34
  - ::getEarliestRevTime(), deprecated in 1.35
* UploadBase::stashFile(), deprecated since 1.28, was removed.
* wfGetRusage(), deprecated since 1.35, has been removed.
* The following CLI options were removed from tests/phpunit.php:
    - use-filebackend
    - use-jobqueue
    - use-bagostuff
  The following options (inherited from Maintenance) were also removed:
    - conf
    - dbuser
    - dbpass
    - dbdefaultgroup
    - globals
    - memory-limit
    - profiler
    - server
  The following options were changed to environment variables:
    - wiki => PHPUNIT_WIKI
    - use-normal-tables => PHPUNIT_USE_NORMAL_TABLES
    - use-filebackend => PHPUNIT_USE_FILEBACKEND
    - use-bagostuff => PHPUNIT_USE_BAGOSTUFF
    - use-jobqueue => PHPUNIT_USE_JOBQUEUE
  This is so that we can use the default PHPUnit entry point (T90875).
* The PHPUNIT_REUSE_DB / --reuse-db option was removed from the phpunit.php
  runner. It had been broken for at least three years already. The original use
  case was speeding up tests on Oracle, but Oracle support was dropped several
  releases ago.
* The MediaWikiPHPUnitTest__endTestHook and MediaWikiPHPUnitTest__startTestHook
  PHPUnit hooks were removed. MediaWikiHooksPHPUnitExtension was also removed.
* EntryPoint::getTextFormatters() was made private without a deprecation period;
  it had no known external callers.
* DatabaseBlock::chooseBlock(), deprecated since 1.35, was removed.
* SpecialPageFactory::getRestrictedPages(), deprecated since 1.36, was removed.
* SpecialBlock::validateTarget(), deprecated since 1.36, was removed.
* The PatchFileLocation trait was removed without deprecation.
* ActorMigrationBase::getExistingActorId() and ::getNewActorId(), emitting
  deprecation warnings since 1.36, were removed.
* Hook handlers implementing the MediaWikiServicesHook hook are now prohibited
  from having services injected. This is because by definition, this hook runs
  before the service container is fully initialized.
* The protected property LocalFile::$metadata was removed without deprecation.
* WatchedItem::getUser(), emitting deprecation warnings since 1.36, has been
  removed.
* AuthManager::singleton(), emitting deprecation warnings since 1.36, has been
  removed.
* The AugmentPageProps class was removed without deprecation. It had no known
  uses.
* Html::infobox(), deprecated since 1.36, was removed.
* ParserOptions::__construct() now requires that the first parameter is a
  UserIdentity object - passing `null` used to fallback to the global
  $wgUser but was deprecated since 1.36.
* ParserOptions::newCanonical() no longer supports the first parameter being
  null (or omitted entirely), which would fallback to the global $wgUser but
  was deprecated since 1.35.
* The SkinTemplatePreventOtherActiveTabs hook, deprecated in 1.35, was removed
  entirely.
* The SkinTemplateTabAction hook, deprecated in 1.35, was removed entirely.
* The SkinTemplateBuildNavUrlsNav_urlsAfterPermalink hook, deprecated in 1.35,
  was removed entirely.
* The SkinTemplateToolboxEndHook, deprecated in 1.35, was removed entirely.
* The following methods of RevisionStore class, formerly emitting deprecation
  warnings, were removed:
  - ::newMutableRevisionFromArray()
  - ::loadRevisionFromPageId()
  - ::loadRevisionFromTitle()
  - ::loadRevisionFromTimestamp()
  - ::listRevisionSizes()
* LogEntry::getPerformer(), deprecated since 1.36, was removed along with
  methods in sub-classes: DatabaseLogEntry, ManualLogEntry, RCDatabaseLogEntry.
* Skin::getRelevantUser() now returns an instance of UserIdentity, and not
  necessarily a User object. There is no known usages in MediaWiki ecosystem
  that were not satisfied with UserIdentity.
* Direct construction of MergeHistory class, deprecated since 1.35, is no longer
  supported. Use MergeHistoryFactory instead. MergeHistory::checkPermissions,
  deprecated since 1.36, was removed.
* Skin::generateDebugHTML(), deprecated since 1.35, was removed. Call
  MWDebug::getHTMLDebugLog() directly.
* The ApiTestCase class no longer interacts with the global $wgUser.
  Previously, the global variable was set at the start of each test, and in
  ApiTestCase::doApiRequest() if a performer was specified $wgUser was
  updated to match, and if no performer was specified $wgUser was used
  instead. Now, $wgUser is not updated, and if no performer is specified
  the reusable TestUser object for the sysop is relied on. Extensions
  or skins that rely on the global $wgUser variable (which has been
  deprecated since 1.35) should instead retrieve the acting user from the
  relevant context source.
* SkinTemplate::makeArticleUrlDetails(), deprecated since 1.35, was removed.
* Skin::makeNSUrl(), deprecated since 1.35, was removed.
* Skin::getRevisionId(), deprecated since 1.34, was removed. Use
  OutputPage::getRevisionId() instead.
* Skin::isRevisionCurrent(), deprecated since 1.34, was removed. Use
  OutputPage::isRevisionCurrent() instead.
* AbstractBlock::parseTarget(), deprecated since 1.36, was removed.
* The ArticleEditUpdates hook, deprecated since 1.35, was removed.
* The `@stable to extend` class CentralIdLookup has following changes:
  - The protected ::checkAudience() method now returns an Authority instead of a
    User instance.
  - A number of its `@stable to override` methods now accept an Authority
    instead of a User instance as the $audience parameter.
  - A number of methods now accept a UserIdentity instead of their User
    parameter.
  - The ::localUserFromCentralId() method now returns UserIdentity and not
    necessarily a User object.
  All extensions that extend this class or use this method were updated to be
  ready to the new behavior.
* WatchedItemStoreInterface::enqueueWatchlistExpiryJob(), deprecated since 1.36,
  was removed.
* ResultWrapper is now abstract. It cannot be directly constructed (T286694).
* The SecondaryDataUpdates hook, deprecated in 1.32, was removed entirely.
* Content::getDeletionUpdates(), was removed. Use
  ContentHandler::getDeletionUpdates() instead.
* Content::getSecondaryDataUpdates(), was removed. Use
  ContentHandler::getSecondaryDataUpdates() instead.
* wfDiff(), deprecated since 1.25, has been removed.
* Language::$mLangObjCache, deprecated since 1.35, was removed.
* Language::$transformData, deprecated since 1.35, was removed.
* Language::transformUsingPairFile() was marked @internal. Its deprecated
  parameters are no longer supported.
* SpecialMute::getTarget(), unused outside of the SpecialMute class, was
  made private.
* The Skin::setupSkinUserCss() method, deprecated in 1.32, was removed. Please
  use skin registration instead.
* The ResourceLoaderSkinModule `legacy`, `content` and `content-thumbnails`
  features were deprecated. Skins should instead select from the features
  listed on [[mw:Manual:ResourceLoaderSkinModule]].
* ParserCache::getKey() and ::getEtag(), deprecated since 1.36, were removed.
* The BaseTemplateToolbox hook, deprecated since 1.35, was removed.
* Previously a capitalize-all-nouns class was added to the body element of
  languages where nouns must be capitalized. This class is no longer added to
  the body tag and must be provided by skins.
* The SkinTemplateOutputPageBeforeExec hook, deprecated since 1.35, was removed.
* Calling Message::toString() without a parameter, which triggered deprecation
  warnings since 1.36, is no longer supported. You can instead use the explicit
  formatting methods directly, such as Message::text() and Message::escaped().
* Article::getContentObject(), deprecated since 1.32, was removed.
* Article::delete(), Article::confirmDelete() and ImagePage::delete() were
  removed. The logic responsible for building the form is being
  moved to DeleteAction, while the actual deletion logic will be moved to a
  separate service.
* WikiImporter::debugRevisionHandler(), unused and for debug only, was removed.
* Content::preloadTransform() now emits deprecation warnings. Instead, please
  use ContentTransformer::preloadTransform(). Extensions defining a content
  model should override ContentHandler::preloadTransform().
* Content::preSaveTransform() now emits deprecation warnings. Instead, please
  use ContentTransformer::preSaveTransform() instead. Extensions defining
  a content model should override ContentHandler::preSaveTransform().
* Constructing WikiPage objects from Title instances that cannot exist, emitting
  deprecation warnings since 1.36, now throws an exception. Additionally,
  WikiPage now implements ProperPageIdentity, rather than just PageIdentity.
* The Skin::bottomScripts() method is deprecated. Please instead use
  OutputPage::getBottomScripts().
* LinksUpdate::getTriggeringUser() now returns ?UserIdentity instead of ?User.
* The LESS mixin `.box-shadow()` (from mediawiki.mixins.less), deprecated since
  1.36, was removed. Use CSS property `box-shadow` unprefixed for all basic
  supported browsers instead.
* The LESS mixin `.flex()` now no longer tries to support the 2009 version of
  the Flexbox specification; support for the 2012 and modern standard versions
  remains unchanged.
* The StorageAwareness::ATTR_SYNCWRITES, StorageAwareness::QOS_SYNCWRITES_*,
  StorageAwareness::ATTR_LOCALITY, and StorageAwareness::QOS_LOCALITY_*
  constants were removed.

=== Deprecations in 1.37 ===
* JobQueue::getWiki(), deprecated in 1.33, now emits deprecation warnings.
* AbstractBlock::getTargetAndType() and ::getTarget() now emit deprecation
  warnings. Use ::getTargetName() and ::getTargetUserIdentity() together with
  ::getType().
* Passing a UserIdentity to WatchlistManager::clearAllUserNotifications() and
  WatchlistManager::clearTitleUserNotifications() is now deprecated. Pass an
  Authority instead.
* Passing LinkTarget to WatchlistManager::clearTitleUserNotifications() and
  WatchlistManager::getTitleNotificationTimestamp(). Pass PageIdentity instead.
* The User class methods ::isWatched(), ::isTempWatched(), ::removeWatch(), and
  ::addWatch() have been deprecated. Use corresponding methods in
  WatchlistManager instead.
* Multiple WatchAction methods have been deprecated in lieu of WatchlistManager:
   - ::doWatchOrUnwatch() use WatchlistManager::setWatch()
   - ::doWatch() -> WatchlistManager::addWatch()
   - ::doUnwatch() -> WatchlistManager::removeWatch()
* WatchAction::getWatchToken() now emits deprecation warnings. Instead use
  CsrfTokenSet::getToken().
* Action::getHookContainer() has been marked as internal. Actions that require
  access to a hook container should have one injected instead.
* The ::getTitle() and ::setTitle() methods in Parser have been deprecated.
  Use ::getPage() and ::setPage() instead.
* Title::isWatchable() has been deprecated. Use WatchlistManager::isWatchable()
  instead.
* Methods and classes related to the primary database, previously referred to as
  'master', have been deprecated, with the new ones replacing them as follows:
  - The DBMasterPos and MySQLMasterPos classes have been respectively renamed to
    DBPrimaryPos and MySQLPrimaryPos.
  - LocalRepo::getMasterDB() -> ::getPrimaryDB()
  - ForeignDBRepo::getMasterDB() -> ::getPrimaryDB()
  - JobQueueDB::getMasterDB() -> ::getPrimaryDB()
  - ForeignDBViaLBRepo::getMasterDB() -> ::getPrimaryDB()
  - DBFileJournal::getMasterDB() -> ::getPrimaryDB()
  - ILoadBalancer::getMasterPos() -> ::getPrimaryPos()
  - IDatabase::getMasterPos() -> ::getPrimaryPos()
  - ILoadBalancer::finalizeMasterChanges() -> ::finalizePrimaryChanges()
  - ILoadBalancer::approveMasterChanges() -> ::approvePrimaryChanges()
  - ILoadBalancer::beginMasterChanges() -> ::beginPrimaryChanges()
  - ILBFactory::beginMasterChanges() -> ::beginPrimaryChanges()
  - ILoadBalancer::commitMasterChanges() -> ::commitPrimaryChanges()
  - ILBFactory::commitMasterChanges() -> ::commitPrimaryChanges()
  - IDatabase::getTopologyRootMaster() -> ::getTopologyRootPrimary()
  - IDatabase::masterPosWait() -> ::primaryPosWait()
  - ILoadBalancer::runMasterTransactionIdleCallbacks() ->
      ::runPrimaryTransactionIdleCallbacks()
  - ILoadBalancer::runMasterTransactionListenerCallbacks() ->
      ::runPrimaryTransactionListenerCallbacks()
  - ILoadBalancer::rollbackMasterChanges() -> ::rollbackPrimaryChanges()
  - ILBFactory::rollbackMasterChanges() -> ::rollbackPrimaryChanges()
  - ILoadBalancer::flushMasterSnapshots() -> ::flushPrimarySnapshots()
  - ILoadBalancer::hasMasterConnection() -> ::hasPrimaryConnection()
  - ILoadBalancer::hasMasterChanges() -> ::hasPrimaryChanges()
  - ILBFactory::hasMasterChanges() -> ::hasPrimaryChanges()
  - ILoadBalancer::lastMasterChangeTimestamp() -> ::lastPrimaryChangeTimestamp()
  - ILoadBalancer::hasOrMadeRecentMasterChanges() ->
      ::hasOrMadeRecentPrimaryChanges()
  - ILBFactory::hasOrMadeRecentMasterChanges() ->
      ::hasOrMadeRecentPrimaryChanges()
  - ILoadBalancer::pendingMasterChangeCallers() ->
      ::pendingPrimaryChangeCallers()
  - ILoadBalancer::forEachOpenMasterConnection() ->
      ::forEachOpenPrimaryConnection()
  - ILoadBalancer::waitForMasterPos() -> ::waitForPrimaryPos()
  - Database::assertIsWritableMaster() -> ::assertIsWritablePrimary()
  - RevDelList::reloadFromMaster() -> ::reloadFromPrimary()
  - ExternalStoreDB::getMaster() -> ::getPrimary()
  - DatabaseMysqlBase::getMasterServerInfo() -> ::getPrimaryServerInfo()
  - MWExceptionHandler::rollbackMasterChangesAndLog() ->
      ::rollbackPrimaryChangesAndLog()
* wfGetLB(), deprecated since 1.27, now emits deprecation warnings.
* wfLocalFile(), deprecated since 1.34, now emits deprecation warnings.
* wfFindFile(), deprecated since 1.34, now emits deprecation warnings.
* wfIncrStats(), deprecated in 1.36, now emits deprecation warnings.
* wfCanIPUseHTTPS() is now deprecated, and always returns true.
* The UserLoadFromDatabase hook has been deprecated. It had no known uses.
* The following methods in ApiPageSet have been deprecated:
   - ::getTitles(), use ::getTargets() instead.
   - ::getGoodTitles(), use ::getGoodPages() instead.
   - ::getMissingTitles(), use ::getMissingPages() instead.
   - ::getGoodAndMissingTitles(), use ::getGoodAndMissingPages() instead.
   - ::getRedirectTitles(), use ::getRedirectTargets() instead.
   - ::getSpecialTitles(), use ::getSpecialPages() instead.
* The following methods from the User class, deprecated in 1.35, now each emit
  deprecation warnings:
   - ::getOptions()
   - ::isIP()
   - ::isUsableName()
   - ::isCreatableName()
   - ::getCanonicalName()
   - ::addAutopromoteOnceGroups()
   - ::getEffectiveGroups()
   - ::getAutomaticGroups()
   - ::getFormerGroups()
   - ::getIntOption()
   - ::getBoolOption()
* The following methods in User were deprecated:
  - ::idFromName() - use UserIdentityLookup::getUserIdentityByName() instead.
  - ::resetIdByNameCache() - in tests, reset service container. No replacement
    needed in production code.
* Use of ActorMigration for any table except revision, deprecated in 1.34, now
  emits deprecation warnings. Instead of getInsertValues(), use
  ActorNormalization::acquireActorId(). Instead of getWhere() and getJoin(),
  do your own join on the actor table.
* DatabasePostgres::remappedTableName() and its dependent constructor parameter
  'keywordTableMap' are deprecated. Reserved identifiers that are used as table
  names should be quoted where necessary.
* LinkCache::singleton(), deprecated since 1.28, now emits deprecation warnings.
* MessageCache::singleton(), deprecated since 1.34, now emits deprecation
  warnings.
* LockManagerGroup::singleton() and ::destroySingletons(), deprecated since
  1.34, now emit deprecation warnings.
* HtmlFileCacheUpdate::newFromTitles() is now deprecated and emitting warnings.
  Use newFromPages() instead.
* SessionProvider ::setLogger(), ::setManager(), ::setConfig(), and
  ::setHookContainer() were deprecated. Use ::init() to inject dependencies, or
  override ::postInitSetup() to do any custom post-initialization configuration.
* AbstractAuthenticationProvider ::setLogger(), ::setManager(), ::setConfig(),
  and ::setHookContainer() now emit deprecation warnings. Use ::init() to inject
  dependencies, or override ::postInitSetup() to do any custom post-
  initialization configuration.
* User::isLoggedIn(), deprecated since 1.36, now emits deprecation warnings. Use
  the method it wraps, User::isRegistered(), instead.
* FileBackendGroup::singleton() and ::destroySingletons(), deprecated since
  1.35, now emit deprecation warnings.
* The first parameter of User::getBlock() should now be an integer using the
  Authority::FOR_XXX constants. Providing a boolean is deprecated.
* ApiBase::addBlockInfoToStatus() is deprecated for use by extensions. It is now
  marked as @internal and may be deleted in the future.
  It should not be necessary to call this method, Authority should be providing
  all relevant information via a PermissionStatus object.
* JobQueueGroup::singleton() was deprecated - use
  MediaWikiServices::getJobQueueGroup() instead.
* JobQueueGroup::destroySingletons() was deprecated. JobQueueGroups are now
  automatically destroyed after tests.
* LinkCache::addGoodLinkObj() has been deprecated, since it is prone to
  corrupting the cache with invalid information. Use addGoodLinkObjFromRow()
  instead. PHPUnit tests must use LinkCacheTestTrait::addGoodLinkObject().
* ContentHandler::getContentText() is now deprecated. Use Content::getText()
  instead.
* LinkCache::addLinkObj() has been deprecated, use PageStore::getPageForLink()
  instead.
* MediaWiki\User\UserNamePrefixSearch::search() previously accepted as its first
  parameter either the string 'public' or a UserIdentity object, to filter
  results for. It now expects an Authority object instead of UserIdentity, and
  providing just a UserIdentity will now trigger a deprecation warning.
* User::getRights(), deprecated since 1.34, now emits deprecation warnings.
* User::changeableGroups() and ::changeableByGroup() now emit deprecation
  warnings, use corresponding methods in UserGroupManager instead.
* User::incEditCount() was deprecated in favor of the new method
  UserEditTracker::incrementUserEditCount().
* RepoGroup::singleton(), ::destroySingleton() and ::setSingleton(), deprecated
  since 1.34, now emit deprecation warnings.
* RecentChange::getPerformer(), deprecated since 1.36, now emits deprecation
  warnings. Use ::getPerformerIdentity() instead.
* ContentHandler::cleanupHandlersCache(), deprecated since 1.35, now emits
  deprecation warnings.
* Category::getTitle() was deprecated in favor of Category::getPage()
* File::getUser() method now emits deprecation warnings, along with its over-
  rides in LocalFile and ForeignApiFile in favor of ::getUploader().
* SpecialBlock::checkUnblockSelf(), deprecated in 1.36, now emits deprecation
  warnings.
* (T284179) The mediawiki.viewport ResourceLoader module is deprecated. You can
  now just use MutationObserver or InterSectionObserver directly, which are
  widely available in all supported JavaScript browsers.
* The following constructor options of DatabaseBlock class will now trigger
  deprecation warnings:
    - the 'byText' property with blocker's name,
    - the 'by' property with blocker's ID,
  For both of these, use the 'by' property with UserIdentity value instead.
* The BeforeResetNotificationTimestamp hook was deprecated.
* ArchivedFile::getUser() ::getRawUser() ::getRawUserText() were deprecated in
  favor of ::getUploader.() ::getRawDescription() was deprecated in favor of
  ::getDescription() with RAW audience parameter.
* When calling LocalFile::newFromRow() or LocalFile::loadFromRow(), passing
  extra fields not requested by ::getQueryInfo() will now trigger deprecation
  warnings. This is to warn callers that deprefixing and automatic assignment of
  such fields will not be done in a future version.
* JobSpecification::getTitle() was deprecated without providing a replacement.
  It wasn't used and job given the purpose of JobSpecification class it is not
  needed.
* The protected method File::getImageSize() is now deprecated.
* BacklinkCache::get() was deprecated, use
  BacklinkCacheFactory::getBacklinkCache() instead.
* Title::getBacklinkCache() now emits deprecation warnings. Instead, use the
  ::getBacklinkCache() method in the BacklinkCacheFactory service.
* MediaHandler::getImageSize(), ::getMetadata(), and ::isMetadataValid() were
  deprecated and should no longer be overridden. Instead, sub-classes should
  override getSizeAndMetadata().
* Deprecated File::getMetadata(). Instead use ::getMetadataArray(),
  ::getMetadataItem() and ::getMetadataItems().
* Message::title() has been deprecated; use Message::page() instead.
* BaseTemplate::getAfterPortlet(), BaseTemplate::renderAfterPortlet(), and the
  BaseTemplateAfterPortlet hook, which were deprecated in 1.35,
  now emit deprecation warnings.
* The LocalFile::getHistory() hook is deprecated.
* Previously the Skin templateDirectory option inside skin.json had to be
  relative to MediaWiki core. This should now be relative to the skin.
* Calling WikiPage::prepareContentForEdit() without a UserIdentity is now
  deprecated.
* User::getEditTokenObject(), ::getEditToken(), and ::matchEditToken() were each
  deprecated. Use CsrfTokenRepository, which is available via IContextSource,
  instead. ::matchEditTokenNoSuffix() was deprecated without replacement.
  It was introduced to be able to provide custom error message if the token
  was submitted, but ending slashes were stripped by some ASCII mangling proxy.
  Use ::matchToken() instead, such proxies are much less common now and there's
  not much benefit in customising the error message.
* ContentHandler::getForTitle(), deprecated since 1.35, now emits deprecation
  warnings.
* User::listOptionKinds(), deprecated since 1.35, now emits deprecation
  warnings.
* WikiPage::doEditContent(), deprecated since 1.32, now emits deprecation
  warnings.
* CentralIdLookup::factory() and ::factoryNonLocal() now emit deprecation
  warnings; obtain an instance from MediaWikiServices instead.
* The class RandomPage was renamed to SpecialRandomPage. The class RandomPage
  is now deprecated.
* BotPassword::invalidateAllPasswordsForCentralId() was deprecated.
* BotPassword::removeAllPasswordsForCentralId() was deprecated.
* The Title class members: $mTextform, $mUrlform, $mDbkeyform, $mNamespace,
  $mInterwiki, and $mFragment have been deprecated to not be used directly.
  Instead, their corresponding accessor methods should be used.
* IDatabase::fetchObject(), ::fetchRow(), ::numRows(), ::numFields(),
  ::fieldName(), ::freeResult() and ::dataSeek() are deprecated. Use the
  corresponding methods in IResultWrapper instead.
* ResultWrapper::unwrap(), DatabaseMysqlBase::fieldType() and
  DatabasePostgres::fieldType() each now emit deprecation warnings.
* Sub-classes implementing Database::doQuery() should return either boolean or
  an IResultWrapper. To do otherwise will now trigger a deprecation warning.
* User::getOptionKinds() and ::resetOptions(), both deprecated since 1.35,
  now emit deprecation warnings.
* The following methods in MWNamespace, all deprecated since 1.34, now emit
  deprecation warnings:
  - ::isMovable()
  - ::isSubject()
  - ::getTalk()
  - ::getSubject()
  - ::getAssociated()
  - ::equals()
  - ::subjectEquals()
  - ::hasTalkNamespace()
  - ::wantSignatures()
  - ::isWatchable()
  - ::getSubjectNamespaces()
  - ::getTalkNamespaces()
  - ::isCapitalized()
  - ::hasGenderDistinction()
  - ::isNonincludable()
  - ::getNamespaceContentModel()
  - ::getRestrictionLevels()
  - ::getCategoryLinkType()
* LogFormatter::styleRestricedElement() has been deprecated in favor of
  LogFormatter::styleRestrictedElement()
* The following hooks related to user preferences were deprecated:
  - UserLoadOptions: use LoadUserOptions instead.
  - UserSaveOptions: use SaveUserOptions instead.
  - UserResetAllOptions: no replacement was provided, the hook is not used.
* Title::isNamespaceProtected(), deprecated in 1.34, now emits deprecation
  warnings.
* UserSelectQueryBuilder::userIds(), ::userNames(), and ::userNamePrefix() has
  been deprecated in favor of ::whereUserIds(), ::whereUserNames(), and
  ::whereUserNamePrefix().
* Manually constructing a MovePage object, deprecated in 1.34, now emits
  deprecation warnings. Use MovePageFactory instead.
* The following deletion-related methods were deprecated:
  - WikiPage::doDeleteArticleReal() (soft) - use DeletePage
  - WikiPage::doDeleteArticleBatched() (soft) - no replacement
  - WikiPage::isBatchedDelete() (soft) - use DeletePage
  - WikiPage::doDeleteUpdates() (hard) - no replacement
  - WikiPage::getDeletionUpdates() (hard) - no replacement
  - Title::isBigDeletion (soft) - no replacement
* Relying on PermissionManager or Authority to check for big deletions
  was deprecated. This is now automatically checked if you use
  DeletePage::deleteIfAllowed(). (T288759)
* The userCan hook now emits deprecation warnings. Use the
  getUserPermissionsErrors or getUserPermissionsErrorsExpensive hooks instead.
* Parser::$mUser public access, and the methods ParserOptions::getUser() and
  Parser::getUser() each now emit deprecation warnings.
* The following methods in the Title class have been deprecated in favor of the
  corresponding methods in the new RestrictionStore service (with different
  names where indicated):
  - ::areCascadeProtectionSourcesLoaded()
  - ::areRestrictionsCascading()
  - ::areRestrictionsLoaded()
  - ::getAllRestrictions()
  - ::getCascadeProtectionSources()
  - ::getFilteredRestrictionTypes()
      -> ::listAllRestrictionTypes()
  - ::getRestrictionExpiry()
  - ::getRestrictionTypes()
      -> ::listApplicableRestrictionTypes()
  - ::getRestrictions()
  - ::isCascadeProtected()
  - ::isProtected()
  - ::isSemiProtected()
  - ::loadRestrictionsFromRows()
* The following Title methods have been deprecated with no direct public
  replacement:
  - ::deleteTitleProtection()
  - ::getTitleProtection()
  - ::flushRestrictions()
  - ::loadRestrictions()
* User::isAllowUsertalk() now emits deprecation warnings. Use User::getBlock()
  and AbstractBlock::isUsertalkEditAllowed() instead.
* Classes used by Preprocessor_DOM have been merged with classes used by
  Preprocessor_Hash, as Preprocessor_DOM was removed in 1.35.
   - PPDPart has been merged into PPDPart_Hash
   - PPDStack has been merged into PPDStack_Hash
   - PPDStackElement has been merged into PPDStackElement_Hash
* By default, the global variable $wgUser is now an instance of the new class
  StubGlobalUser rather than User, and the first time it is used it will emit
  deprecation warnings (the $wgUser variable was deprecated in 1.35). For
  extensions that read from this variable, please use a relevant ContextSource
  instead, falling back to RequestContext::getMain() if none is available.
* Collation::singleton() and ::factory() were deprecated; obtain an instance of
  the CollationFactory from MediaWikiServices instead.
* Title::getDefaultNamespace() has been deprecated to be removed because there
  are no known callers/consumers.
* With removal of the stub threshold feature, the following methods now emit
  deprecation warnings:
  - LinkRenderer::setStubThreshold() and ::getStubThreshold() - no replacement.
  - LinkRendererFactory::createForUser() - calling ::create() is now sufficient
  - ParserOptions::setStubThreshold() and ::getStubThreshold() - no replacement.
  - User::getStubThreshold() - no replacement.
* The ArticleDelete and ArticleDeleteComplete hooks were deprecated. Use
  PageDelete and PageDeleteComplete instead.
* The ArticleUndeleteLogEntry hook was deprecated without replacement.
* The following LESS mediawiki.mixins have been deprecated:
  - .box-sizing()
  - .transform()
  - .transform-origin()
  - .transition()
  - .transition-transform()
* The `UndeleteForm::undelete` hook was deprecated. A new hook was
  introduced, `PageUndelete`, that provides handlers with more information and
  is also called for non-UI requests. The capability of replacing the
  PageArchive object has been removed, as that violates the laws of nature.

=== Other changes in 1.37 ===
* WatchlistManager::addWatch() and WatchlistManager::addWatchIgnoringRights(),
  which replace User::addWatch(), now call the WatchArticle and
  WatchArticleComplete hooks.
* WatchlistManager::removeWatch() and
  WatchlistManager::removeWatchIgnoringRights(), which replace
  User::removeWatch(), now call the UnwatchArticle and UnwatchArticleComplete
  hooks.
* The overridable postInitSetup() method was added to the
  AbstractAuthenticationProvider class. A provider can override postInitSetup()
  to do any custom post-initialization configuration.
* The overridable postInitSetup() method was added to the SessionProvider
  class. A provider can override postInitSetup() to do any custom
  post-initialization configuration.
* The protected getConfig() method was added to the SessionProvider class.
  Use SessionProvider::getConfig() to get a config.
* The DBAccessBase class is deprecated. Classes that used to extend it
  should get a load balancer (factory) injected in the constructor instead.
* ActorNormalization::acquireActorId() now requires IDatabase parameter.
  Not providing one emitted deprecation warnings since 1.36.
* Anti-lock constants ALF_PRELOAD_LINK, ALF_NO_BLOCK_LOCK, ALF_NO_LINK_LOCK
  and ALF_PRELOAD_EXISTENCE have been removed. They're unused since 1.25.
* (T278036) CSS class 'mw-htmlform-field-autoinfuse' used by some forms has been
  renamed to 'mw-htmlform-autoinfuse'.
* User::newFromRow() does not accept pre-loaded user preferences under
  $data['user_properties'] anymore. This optimization was not used.
* The following files change the letter case of the file names:
  - SpecialRandompage.php -> SpecialRandomPage.php
  - SpecialRandomredirect.php -> SpecialRandomRedirect.php
  - SpecialRandomrootpage.php -> SpecialRandomRootPage.php
* Media files which are uploaded server side using the importImages.php
  maintenance script will now have the "mw-server-side-upload" change tag.
* (T284917) The stub threshold feature has been removed.
* Skin::getPoweredBy() and Skin::getCopyrightIcon() have been deprecated as they
  are only designed for use by skins extended BaseTemplate. You can move calls
  to instead use BaseTemplate::getPoweredByHTML() and ::getCopyrightIconHTML()
  respectively.
* The SkinGetPoweredBy hook is deprecated. No replacement is provided.
* HTMLTitleTextField didn't support interwiki titles well previously.
  Starting with 1.37, HTMLTitleTextField has a new parameter, 'interwiki',
  which can be used to control acceptance of interwiki titles. To provide
  a transitional period, the default value ('interwiki' => null) ensures
  MW will have the same behavior as before (logging a deprecation warning).
  In 1.38, the default behavior will change to "interwiki links aren't allowed".

== Compatibility ==

MediaWiki 1.37 requires PHP 7.3.19 or later, or PHP 7.4.3 or later, and the
following PHP extensions:

* ctype
* dom
* fileinfo
* iconv
* intl
* json
* mbstring
* xml

Support for PHP 8.0 is not yet complete.

MySQL/MariaDB is the recommended DBMS. PostgreSQL or SQLite can also be used,
but support for them is somewhat less mature.

The supported versions are:

* MySQL 5.5.8 or later
* PostgreSQL 9.4 or later
* SQLite 3.8.0 or later

== Online documentation ==
Documentation for both end-users and site administrators is available on
MediaWiki.org, and is covered under the GNU Free Documentation License (except
for pages that explicitly state that their contents are in the public domain):

       https://www.mediawiki.org/wiki/Special:MyLanguage/Documentation

== Mailing list ==
A mailing list is available for MediaWiki user support and discussion:

       https://lists.wikimedia.org/mailman/listinfo/mediawiki-l

A low-traffic announcements-only list is also available:

       https://lists.wikimedia.org/mailman/listinfo/mediawiki-announce

It's highly recommended that you sign up for one of these lists if you're
going to run a public MediaWiki, so you can be notified of security fixes.

== IRC help ==
There's usually someone online in #mediawiki on irc.libera.chat.