Originally Posted by carleton

If I remember correctly:

For anything under Elite Nationals:
- You can be CAT5 for any time trial (flying 200, 500M, Kilo, 2K, 3K, 4K, team sprint, team pursuit).
- You must be CAT3 for mass start (keirin, scratch, points, madison, miss and out, omnium)
- I can't recall if you need a CAT3 for Match Sprints or not.
- Some events, like AVC events may have their own restrictions, like the Elite being Pro/1/2 only and Masters/Women can be CAT3. It's really up to the promoter.

If I remember correctly: Men must be CAT2 to participate in any event at Elite Nationals. Women must be CAT3 for any event at Elite Nationals (I think).