Little yellow map pin

The little yellow map pin was sent to new members stuck in a piece of cardboard.

Traditionally, a little yellow map pin (sometimes abbreviated "LYMP"), worn in a member's lapel, was the "secret" symbol of Mensa membership intended to enable Mensans to recognize one another upon meeting by chance. For many years, such a pin was included in the new-member packet sent to those joining American Mensa, and perhaps some other national Mensas did it as well. However, the custom of wearing them gradually went into disuse. Possibly because not so many people wear suits- fewer lapels.