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

Issue #2478483 by Wim Leers, Fabianx: Introduce placeholders (#lazy_builder) to replace #post_render_cache

Issue #2290263 by joshi.rohit100, amitgoyal, er.pushpinderrana, cs_shadow: Make Filter plugin developer info more discoverable

Issue #2217877 by Wim Leers, Dave Reid, damiankloip, xjm, chx | catch: Fixed Text filters should be able to add #attached, #post_render_cache, and cache tags.

Issue #2099741 by Wim Leers, wwalc, mr.baileys, eaton, dstol, nod_, effulgentsia: Protect WYSIWYG Editors from XSS Without Destroying User Data.

Issue #2184315 by Wim Leers: Move filter_get_filter_types_by_format() and filter_get_html_restrictions_by_format() onto FilterFormatInterface.

Issue #1898416 by Cottser, joelpittet, drupalninja99, mikl, drupalmonkey, bradwade, pwieck, ezeedub, kerasai, disasm | c4rl: Filter.module - Convert theme_ functions to Twig.

Issue #1847002 by tim.plunkett, effulgentsia, msonnabaum: Move entity type classes from Drupal$provider\Plugin\Core\Entity to Drupal$provider\Entity.

Issue #1936392 by Wim Leers: Configure CKEditor's 'Advanced Content Filter' (ACF) to match Drupal's text filters settings.