Rehearsal invitation ideas!?!

Help needed!
What are the Rehearsal Invites supposed to say???! i have 2 days to make them and send them out!

I think they could be jsut like any other invitation wtih
For:
From:
Date:
Time:
Place:
RSVP:
etc. but I'm not 100 % sure, some people just type it up on a pretty piece of paper the above information and send it out....