Requesting a charity contribution rather than a gift: It is very poor wedding invitation etiquette to even mention gifts but most invited guests will enquire if there is a wedding gift list. The other members of the wedding party should be encouraged to put the word around as to what the bride and groom would prefer.
There are some extra stationery things that are required when ordering invitations. RSVP cards are required if couples are having a sit down dinner. Couples need to know the guest count to figure out how much food to order. It is no longer tradition to pay for postage for guests to send the RSVP card back to the couple. Send invitations early to give guests plenty of notice about the wedding. They should be sent out at least two months before the wedding and no more than four months before. Make the RSVP date between four and six weeks before the wedding. This helps you know exactly how many guests will show up.