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

Issue #2502621 by Pravin Ajaaz, hussainweb, Peacog, jhodgdon, ivanjaros: Replace implement notes with inheritdoc tag

Issue #2570285 by mr.baileys, cpj, stefan.r, alexpott, nlisgo, joelpittet, Aki Tendo, borisson_, chx, dawehner, s_leu, Berdir: Make sure TranslatableMarkup accepts string values only

Issue #2576533 by alexpott, stefan.r, Wim Leers, dawehner, xjm, effulgentsia, catch: Rename SafeStringInterface to MarkupInterface and move related classes

Issue #2569069 by stefan.r, mr.baileys, alexpott, lauriii: Replace TranslationWrapper with TranslatableString and deprecate TranslationWrapper

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 #2546618 by plach, dawehner, chx, bojanz: Replace the Symfony Translation component with a custom interface since we don't use it

Issue #2552867 by jhodgdon, Gábor Hojtsy, pjonckiere: Document DrupalTranslator::transChoice()'s non-standard formatPlural() usage

Issue #2309737 by rpayanm, hussainweb, max-kuzomko, herom, millerbennett, ianthomas_uk, quietone, Sutharsan, sumitmadan, toddmbloom: Remove deprecated format_plural usage

Issue #2340667 by YesCT, Pedro Lozano, alexpott, martin107: Protect Drupal\Core\Language\Language::id, and use getId().

Issue #2246665 by jaredsmith, martin107, YesCT, filijonka, tstoeckler: Typehint with Drupal\Core\Language\LanguageInterface instead Drupal\Core\Language\Language.

Issue #2070369 by herom, bdgreen, Mac_Weber, InternetDevels, sidharthap, JeroenT: Remove all calls to deprecated function language().

Issue #1754246 by webflo, swentel, penyaskito, andypost, alexpott, YesCT, dagmar: Languages should be configuration entities.

Issue #1620010 by dawehner, ParisLiakos, plach, jibran: Move LANGUAGE constants to the Language class.

Issue #1845546 by fago, EclipseGc, attiks, effulgentsia: Implement validation for the TypedData API.