An announcment is sent that would go something like this: You are cordially invited to attend the wedding reception of Phil and Nancy. Please join us at the reception hall on Saturday, May third at 2:00 PM. Make sure you address the announcment to Mr. & Mrs., Mr., Miss or Ms. This way if you don't want children to attend it will be quite clear since you didn't put Mr. & Mrs. and family. If you don't mind singles bringing a friend then put a card inside saying so. Hope this helps.