We want to avoid issues like this:
- A developer is trying to understand the messaging changes in Moodle 3.5.
- They see that message_user_actions.action conitains values 1 or 2.
- They go to look in lib/db/install.php to see what this means.
Acutal result: No info.
Expect result: There should be a comment saying something like "1 = read, 2 = deleted, see core_message\api for the corresponding named constants."
It should be possible to teach CiBoT to check that these comments are present, like it checks PHPdoc comments for completeness.