If your relatives or friends are engaged to be married, their fiances (or fiancees) must be invited; their live-in romantic partners must be as well. However, if they are only dating, you need not invite their boyfriend or girlfriend. Should you decide to include some dates and not others, draw your cut-off line at a clearly identifiable place and communicate it to everyone who is not allowed to invite someone to accompany them.
Beware, many unmarried people find it tremendously upsetting to not be allowed to bring a date. Prepare them for the idea and pay careful attention to where the singletons sit during dinner.
As for your attendants -- letting them bring an escort would be a considerate gesture. It's not required, but they've done a lot for you.
HOW DO I TELL PEOPLE CHILDREN ARE NOT INVITED?
Not everyone knows that the only people invited to an event are the ones to which the invitation is addressed. If you have friends who feel their little ones are always included, a quick phone call to tell them that your reception isn't set up for children will get your point across―and it's nicer than printing "No children, please" on the invitation or the response card.
HOW DO I LET PEOPLE KNOW WE WON'T BE SERVING ALCOHOL?
Even though your choice of what to serve really doesn't require an explanation, it's not a bad idea to give your guests a heads up about alcohol, says Post. The best way is by word of mouth, she says; ask your family and your wedding party to pass along the information as they would any other details about the wedding and reception. You could also casually mention it to guests with a simple "By the way, there won't be any alcohol served at the reception."
If your guest list is large or you prefer to let people know in writing, add a discrete note on the reception page of your wedding website: "Please know that alcohol will not be served." The same wording could also unobtrusively appear on any insert you include with your reception invitation, such as directions to the venue or other logistics, but Post says this should be a last resort. Never include it on the wedding invitation itself.
HOW DO I INVITE GUESTS TO ADDITIONAL WEDDING EVENTS?
If you've planned extra events for all the guests -- a welcome dinner, rehearsal dinner, a round of golf on Saturday morning, a post-wedding brunch just to name a few -- it's a good idea to put this information into the invitation as well. This information can also go on the wedding website, but that that's not a substitute for a direct invitation.
However, if not everyone is invited to everything, use separate invites. Including those events in the invitation may lead your guests to think that everyone is invited, creating awkward situations when a conversation reveals that someone was left out.
HOW DO I INFORM GUESTS OF THE DRESS CODE?
Guests sometimes wonder what to wear to a wedding; you can tip them the wink by adding a line to the lower right corner of the invitation indicating "black tie" or other information. If the hint you want to give gets a little more complicated (for example, "wear lawn-friendly shoes"), a separate card might be useful.
HOW DO I TELL MY GUESTS ABOUT OUR GIFT REGISTRIES?
Even if your store provides them, do not include little cards that contain information about your registry. And don't add the registry information to your invitation itself in any other way. It's impolite for you to start the conversation about gifts. Even if some guests find it convenient, others will think it seems greedy. Ask family and friend to spread the news when people ask; you can also put this information one level down on a wedding website, and mention it to anyone who asks you directly.
HOW DO I INCLUDE TRAVEL AND ACCOMODATION INFORMATION?
Locating a hotel (or two) that's convenient and affordable for your out-of-town guests is a common courtesy; you can pass this along using an insert card. You needn't include all the features; just give the basic room rate, plus contact information.
Providing specific travel information to the city itself is generally not necessary. Airline information and road atlases will help people figure out their own travel plans.
If you want to avoid this enclosure all together, you can include all this information on your website. A grandparent who is not online can get theirs from you directly.
SHOULD I INCLUDE A LINK TO OUR WEDSITE?
In the technological and ecological age, mentioning the wedding website on your invitation is completely acceptable. Place the web address, or URL, in the lower left corner of the invitation, in the spot traditionally used for noting R.S.V.P. information. If your invitation is getting crowded, a business-card-size enclosure can convey this data (it can function as an at-home card as well, giving people your post-wedding contact info for their address book)