wear what you like. The forums rules only apply here on the forum not in real life.

The best to wear (IMO) is your local bike club jersey (after you join), race jersey (that you have completed), LBS jersey, matching bike manufacture jersey, or just a plain coloured jersey.

I know pro team jerseys are against the rules but many wear them. I have a Cervelo test team jersey (the team is now defunct so it looks like a brand jersey)

but seriously, no one cares what you wear, but Bibs are a must.