Issue #3431452 by godotislate, smustgrave, alexpott: Rename RenderElement and FormElement plugin abstract classes to RenderElementBase and FormElementBase

Issue #3421439 by godotislate, sorlov, quietone, smustgrave, alexpott, larowlan, longwave, andypost: Convert form and render element plugin discovery to attributes

Issue #3420984 by godotislate, andypost, smustgrave, larowlan, alexpott: Convert Layout DisplayVariant, PageDisplayVariant discovery to attributes

Issue #3409982 by claudiu.cristea, longwave, alexpott, catch, Ghost of Drupal Past: [D10.2 regression] Theme suggestions cannot alter variables anymore

Issue #3393955 by quietone, xjm, smustgrave: Correct $suggestions documentation in hook_theme_suggestions_alter()

Issue #3157353 by Utkarsh_33, lauriii, dww, smustgrave, longwave, narendraR, quietone, larowlan, catch, Berdir, omkar.podey: Provide a mechanism to mark entire twig templates as deprecated

Issue #3375497 by Yujiman85, xjm, joachim: Unclear term 'internal library name' in theme API documentation

Issue #3375494 by Yujiman85, joachim, smustgrave: incorrect sample code in docs for hook_library_info_build

Issue #2921133 by quietone, VladimirAus, xjm, ankithashetty, longwave, Prem Suthar, smustgrave, benjifisher, AaronMcHale: Remove "Please" from the codebase

Issue #3270148 by jonathanshaw, murilohp, catch, smustgrave, longwave, larowlan, andypost, alexpott, quietone: Provide a mechanism for deprecation of variables used in twig templates

Issue #3268838 by quietone, TR, smustgrave, xjm: Fix functions and test modules for Drupal.Commenting.DocComment.ShortSingleLine

Issue #3343198 by andy-blum, murilohp, smustgrave, safetypin: Improve documentation of hook_theme_suggestions_HOOK_alter()

Issue #2867796 by murilohp, kkalashnikov, sophiavs, ameymudras, Ratan Priya, anagomes, alexpott, joachim: hook_theme() docs for path are inaccurate

Issue #3239980 by longwave, lauriii, kostyashupenko, xjm, catch, bnjmnm, nod_, bbrala: Deprecate Modernizr

Issue #3304285 by longwave, Spokje, bbrala, ravi.shankar, quietone, phenaproxima: Remove Seven from core

Issue #2157567 by Ratan Priya, smustgrave, lucassc, quietone, joachim: unclear explanation of 'path' in hook_theme() docs

Issue #1014086 by catch, nod_, martin107, quietone, dww, mariacha1, Spokje, yogeshmpawar, pounard, Wim Leers, mfer, mikeytown2, mbutcher, moshe weitzman, Fabianx, borisson_, alexpott, donquixote, sun, andypost, dawehner: Stampedes and cold cache performance issues with css/js aggregation

Issue #3259188 by alexpott, dww, chr.fritsch: Extend post update system to provide themes a way to install newly-required dependencies

Issue #3258931 by nod_, hooroomoo, xjm, catch, effulgentsia, Wim Leers: Deprecate backbone and tag it internal

Issue #3097889 by longwave, paulocs, anushrikumari, SenthilMohith, andypost, Gábor Hojtsy, catch, lauriii, Wim Leers: Remove deprecated theme functions

Issue #3175287 by murilohp, quietone, SivaprasadC, ankithashetty, anmolgoyal74, sarvjeetsingh, xjm, longwave: Remove accidentally duplicated words in code comments

Issue #3247650 by Sutharsan, larowlan: Make it clear that hook_page_attachments is not called in themes

Issue #2938969 by msankhala, dhirendra.mishra, paulocs, TR, MerryHamster, alexpott, jofitz, longwave, Manuel Garcia, tameeshb, boaloysius, Yasiru Nilan, xjm, wturrell, ritzz, ZeiP, darrenwh: Replace drupal_render() in docblock and comments outside of @param, @return, @Link, @see and outside of @code - @endcode

Issue #2347783 by kim.pepper, andypost, almaudoh, gumanist, aleevas, rodrigoaguilera, Berdir, saurabh-2k17, Spokje, dhirendra.mishra, alexpott, paulocs, izus, Wim Leers, KapilV, naveenvalecha, anmolgoyal74, subson, yo30, harsha012, mrinalini9, daffie, voleger, dww, fietserwin, tim.plunkett, joachim, larowlan: Deprecate drupal_get_path() and drupal_get_filename() and replace with ExtensionList::getPath() and ExtensionList::getPathname()

Issue #3138746 by jungle, rajandro, sja112, longwave, jameszhang023, quietone, dww: Fix 45 "shouldBeCamelCased" and related typos in core

Issue #3064854 by markcarver, andypost, johnwebdev, lauriii, ridhimaabrol24, Hardik_Patel_12, Charlie ChX Negyesi, jhodgdon, aleksip, alexpott, Fabianx, Chi, Wim Leers: Allow Twig templates to use front matter for metadata support

Issue #2848367 by mlncn, jp.stacey, kunalkursija: Render API overview example of placeholders either incorrect or misleading

Issue #3151091 by dww, rik-dev, alexpott: Replace use of whitelist/blacklist in \Drupal\Component\Utility\Xss and its test and core/lib/Drupal/Core/Render/theme.api.php