Have you ever opened a wedding invitation and noticed the letter “M” followed by a blank line on the RSVP card? At first glance, it might look like a mistake or an unusual question. In reality, this small detail comes from traditional wedding etiquette and is still used on some formal invitations today.

The letter “M” is intended to begin a courtesy title, such as Mr., Mrs., Ms., or Miss. Guests traditionally complete the line with their preferred title and name. For example, someone might write “Ms. Sarah Johnson” or “Mr. and Mrs. John Smith.” The letter provides a starting point for responding formally to the invitation.

This custom reflects an era when written correspondence followed more rigid rules of politeness. Titles were commonly used in formal letters, and wedding invitations often followed the same conventions. Although social customs have changed over time, some couples and stationery designers continue to use the traditional “M” because it gives RSVP cards a classic, elegant appearance.

If you receive an RSVP card with this letter, there is no need to feel confused. Simply write your name clearly on the line, including a title if you wish. If the format does not suit your circumstances, the most important thing is to make sure the couple can identify your response. You should also complete any other requested information, such as whether you will attend and your meal selection.

Today, many couples choose more modern wording, such as “Name(s)” or “Please write your full name,” to make their invitations easier for everyone to understand. Nevertheless, the little “M” remains a familiar detail on traditional wedding stationery. The next time you see it, you will know that this seemingly mysterious letter is simply a small reminder of how wedding customs have evolved over generations.