I wonder why some tags placed under questions look slightly like 3d-buttons, but others look like 2d with a thicker, darker border? I only notice a difference here on Meta SO.
What's the difference?
Thick grey border - Required tag
Each question must include at least one of these tags:
Red tags - Moderator only
Only moderators can set these to a question:
Questions migrated from the other sites to Meta, along with those older than the tag requirements, may slip through without a required tag.