Issue #3222251 by bbrala, longwave: [November 8, 2021] Replace all isset constructs with the null coalescing operator

Issue #3055198 by catch, longwave, mikelutz, alexpott: [Symfony 5] Symfony/Component/EventDispatcher/Event is deprecated in Symfony 4.3 use Symfony/Contracts/EventDispatcher/Event instead

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 #2708179 by anoopjohn: Fix 'Drupal.Commenting.FunctionComment' coding standard - Issues related to @throws

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

Issue #2224887 by alexpott, Berdir, Gábor Hojtsy, Jalandhar: Language configuration overrides should have their own storage.