Changelog / Description:

• New GPG key for GNU ELPA package signature checking.
• New option ‘help-enable-completion-auto-load’, allows disabling the new feature introduced in Emacs 26.1 which loads files during completion of ‘C-h f’ and ‘C-h v’ according to ‘definition-prefixes’.
• Emacs now supports the new Japanese Era name.

Source: https://ftpmirror.gnu.org/emacs/emacs-26.3.tar.gz