What is wrong with using the following on an invitation?
(1) Please RSVP
(2) hors d'oevres
(3) At the home of Susie and Rick Martin, 110 Upland Terrace, Riverdale, Michigan 59043
(4) Regrets only
(1) It's redundant. You're saying "please please." Use please reply or RSVP. It is French for Repondez s'il vous plait (please respond). If you don't hear from the person and it's three days before the party, it's perfectly proper to call them and say "Caroline, I hope you're coming. I have to give the caterer the final count." Usually the answer is yes!
(2) It's spelled incorrectly. Do you know the correct spelling? This is incorrect on 75% of business and social invitations I see.
(3) If it's a local party/event/fundraiser, you don't need the state UNLESS you're inviting people from other states. You never put a zip code in the body of an invitation.
(4) Never use this! You'll never know how many are coming and honestly, it's like saying "I don't care if you show up or not!" Just say please reply because this way you have to hear from everyone. If you feel you have to put a date to reply by that's up to you but I wouldn't.
(5) Always put an area code.
Note: I like to vary my guests at parties I give so I don't invite the same people every year. The second year I hosted one particular theme party, a former guest called me to say, "Pamela, I didn't receive an invitation to your party. Did you forget to invite me?" I, of course, said "Paige, I hope you can come. It's......" She brought me a fabulous hostess gift so it all worked out.