The single **“M”** on a wedding RSVP card can leave guests wondering what they are supposed to write. Some may think it means “Maybe” or refers to meal choices, but its meaning is much simpler. Traditionally, the “M” is the beginning of a courtesy title, such as **Mr., Mrs., Ms., or Miss**, followed by the guest’s name.

The practice comes from older wedding and invitation etiquette, when formal titles were commonly expected on correspondence. Because these traditions are less familiar today, the lone letter can seem confusing or outdated. In reality, it is simply a prompt asking guests to provide the appropriate title and name.

Modern wedding etiquette is much more flexible. Guests do not have to follow the traditional format exactly and can use the title they prefer or simply write their name. The purpose is to make the RSVP clear, not to test whether someone knows formal etiquette rules.

Even though wedding invitations have become more casual, many traditional RSVP designs continue to include the “M.” Understanding its history makes the mysterious letter much easier to recognize and shows how older customs continue to appear in modern celebrations.

Ultimately, the most important thing is responding clearly and on time so the couple can plan their wedding properly. As the original article puts it, **“Understanding the origin of the ‘M’ turns an awkward guessing game into a simple, interesting piece of history.”**