On wedding RSVP reply cards, you'll often see a "M" followed by a line. Many people have no idea what this means, especially younger generations. Thankfully, your guests will likely do a quick internet search and figure it out.
This custom dates back to a time when inviting people to weddings was a bit more formal.
The "M" in the reply card is meant to signify the first letter of your title - the choices are Mr., Mrs., Ms., and Miss.
So, for example, if the RSVP card has been sent to Jane and David Smith, they would write "M"r. and Mrs. David Smith on that line. If it is addressed to your single niece, she would write "M"iss Jessica Smith on that line.
So, hopefully this clears things up. Of course, things get confusing if you are inviting doctors or military personnel to your wedding. Their official titles aren't in that list I mentioned above. Generally they will have to fit themselves into that format or cross it out.
Now, in modern times couples are not as keen on this tradition. Many people are not fans of using titles these days, especially between grownups. They want a wedding that is more casual and more in line with their personalities. So what are some alternatives?
We've seen people replace the "M" with "Name(s)". This is probably the best alternative. If you leave it blank and just have a line to fill out, we suspect that your guests will be even more confused about filling it in and they may not fill out anything at all on that line.
Others suggest having a blank space where you can write in the invited guests on the RSVP card before you send them out. This does help clarify who has been invited if you don't have an outer envelope. But you can also add that information in the mailing address on the invitation envelopes. So it's not necessary. The problem with writing in the names is that you may not end up knowing precisely who is and who is not coming to the wedding. If the guests write in the names themselves, then you will know.
RSVP card wording is somewhat inelegant, as you can never really ensure you'll get the super accurate information back that you want. Back in days long past, RSVP cards were not sent out, as guests were expected, by courtesy, to respond on their own... generally with a handwritten, mailed note. These days, modern couples are considering other options to mailed RSVP cards. Some couples are having people RSVP by email or phone. Others are using wedding websites.