What needs to be included on the invitation?
Heading
• The type of occasion (birthday party, baby shower, etc).
• The name of the person for whom the party is being held.
   For school age children, it’s helpful to include your child’s first and last name in the heading to avoid any confusion.
Example:  “Join us for some birthday fun!  Victoria Wrigley is turning One!”
          
Body
• Day and date of the party
• Time
   I usually include a start and end time. Unless it’s an open-ended family event, it’s helpful for parents to know how long
   the party will be and/or when to pick up their children.
• Location of the Party and the address
Example:  Saturday, March 15
                   2:00 P.M. To 4:00 P.M.
                   Baily’s Ice Cream Parlor
                   134 Whistler Street
                   Hampton
Example Sleepover:  
                  Friday, March 14 at 6:00 P.M. to
                  Saturday, March 15 at 10:00 A.M.
                  15 Willow Street
                  Rockville

Closing
• RSVP or Regrets Only line with your name, phone number, deadline and possibly your email address.
• Special Instructions such as “Bring a bathing suit and towel.”
• Rain Date – If your party will be held outdoors and cannot be held if it rains, include an alternate date or instruction.
 
 
RSVP Information
In French, RSVP is an abbreviation for "réspondez s'il vous plait” or “respond please”.  If you wish to be completely proper, you would use “R.s.v.p.”   In lieu of RSVP, some people use “Regrets Only” which means you assume they are attending unless they call otherwise. 
 
Personally I like to use RSVP and include a deadline that is about a week before the party. This gives me time to purchase any extra party supplies or favors, and if necessary, provide a guest count to a party facility. 
 
Using RSVP also gives me a polite way to call guests who haven't responded.  There have been several times when my children have forgotten to give me an invitation they received at school.  It’s embarrassing, but it happens.  If I haven’t heard from someone on our guest list, I call the parent and say, “Hi, this is Laurie.  I was calling about Scott’s party.  It’s next week, and we really hope Blake can come.  We hadn’t heard from you and just wanted to be sure you received the invitation.”
 
RSVP should include your name, phone number, the deadline date, and possibly an email address. 
 
Here are a few RSVP formats:
RSVP to Laurie Wrigley by June 1, 301-956-1616 or by email at laurie.wrigley@kaboose.com.
R.s.v.p.
Kindly respond to…
Please reply to…
Regrets only, …
 
Some people even use clever RSVP lines that match a theme.
For instance, for a farm or horse party, you might use “Yeahs or Neighs”. 
 
I’m going to add a note about my personal pet peeve.  Some people like to print, “RSVP to my mommy…”, but do not include a name. It’s cute, but makes it awkward for someone who doesn’t know the mother to respond.  It feels silly to call and have to say, “Hi, this is Laurie, I’d like to speak with Jack’s mommy."