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.
A mistake on the address or other pertinent information can require expensive reprints. Do not order an invitation that does not match the style of the wedding or that gives the wrong impression. The number of invitations you send will depend on the number of guests that are being invited. Make a list of all the people both the bride and groom want to invite. Break the numbers down into single people and couples or families. Each group of people being invited should only be sent one invitation.