Issue #2572787 by alexpott, mfernea, attiks, andriyun, andypost, RoSk0, hussainweb, klausi, martin107: Fix 'Drupal.WhiteSpace.CloseBracketSpacing' coding standard

Issue #2873696 by nvexler, wengerk, gido, Jo Fitzgerald, xjm: Add @internal to core classes, methods, properties to Form Classes

Issue #2722609 by anoopjohn, mfernea, Jo Fitzgerald, chishah92, druprad, martin107, Mile23: Fix Drupal.Commenting.FunctionComment.ParamNameNoMatch

Issue #2776975 by joelpittet, dawehner, tim.plunkett, xjm, pfrenssen: March 3, 2017: Convert core to array syntax coding standards for Drupal 8.3.x RC phase

Issue #2719695 by alexpott, Mile23: Fix 'Drupal.Classes.ClassDeclaration.CloseBraceAfterBody' coding standard

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2422481 by akalata, lokapujya, joelpittet: Convert language negotiation theme table to table #type

Issue #2570355 by Sutharsan, stefan.r, kgoel, josephdpurcell, joelpittet, justAChris, dawehner, pfrenssen, pwolanin, David_Rothstein, catch: Replace remaining !placeholder and @placeholder with :placeholder for URLs

Issue #2557113 by stefan.r, alexpott, dawehner, joelpittet, cilefen, lauriii, plach, catch, chx, xjm: Make t() return a TranslationWrapper object to remove reliance on a static, unpredictable safe list

Issue #2561259 by stefan.r, lauriii, joelpittet, andypost: Cast (optgroup) array keys that may hold translated strings to string

Issue #2459971 by Gábor Hojtsy: The langcode key on configuration files is not explicit in configuration schema

Issue #2392319 by alexpott, effulgentsia: Config objects (but not config entities) should by default be immutable

Issue #2328293 by keopx, JeroenT, ianthomas_uk, ashutoshsngh, rpayanm, hudo, a_thakur: Remove usage of language_list()

Issue #365615 followup by attiks, YesCT, Gábor Hojtsy, mgifford, Albert Volkman, plach, webwarrior, David_Rothstein, penyaskito, smokris | yang_yi_cn: Fixed Followups: Language detection not working correctly for most Chinese readers (and add a user interface for all browser language mappings).

Issue #2341341 by YesCT, martin107, vijaycs85, fran seva: Change public 'name' property access on languages to getName() and add back setName().

Issue #2335659 by tim.plunkett, dawehner, effulgentsia, sun: Remove FormState ArrayAccess usage from core.

Issue #2308821 by tim.plunkett: Replace FormErrorInterface with $form_state->setErrorByName() and $form_state->setError().

Issue #2254495 by sun, ParisLiakos, alexpott: Followup to Move language_admin_predefined_list to ConfigurableLanguageManager.

Issue #2254495 by ParisLiakos, alexpott: Move language_admin_predefined_list to ConfigurableLanguageManager.

Issue #2239065 by tim.plunkett | webchick: Overridden config bleeding through to configuration forms.

Issue #2098119 by beejeebus, alexpott, chx: Replace config context system with baked-in locale support and single-event based overrides.

Issue #2145007 by tim.plunkett, h3rj4n: Convert form_set_error() in FormBase classes to use FormErrorInterface.

Issue #2089627 by tim.plunkett: Move \Drupal\system\SystemConfigFormBase to \Drupal\Core\Form\ConfigFormBase.