To help the initiative to update all deprecated code for Drupal 9 we need a standardized format for deprecation messages.
New issue for discussion:
Issue #3024461: Adopt consistent format for deprecation messages.
Having a machine readable format for deprecation messages will allow us to develop tools on api.drupal.org to keep track of the current status of deprecated code in Drupal core and contributed modules. This will help drive the initiative to update all deprecated code before the release of Drupal 9.
Interested in helping out?
You can get started quickly by helping us to update an issue summary or two or dive in and check out the full list of open proposals and see if there's anything you'd like to champion!