Facing Identification Mark

The Facing Identification Mark, or FIM, is a bar code designed by the United States Postal Service to assist in the automated processing of mail.

The FIM is a set of vertical bars printed on the envelope or postcard near the upper edge, just to the left of the postage area (the area where the postage stamp or its equivalent is placed).

The FIM is a nine-bit code consisting of ones (vertical bars) and zeroes (blank spaces).

The following five codes are in use: All defined FIMs start and end with a bar, and are palindromic, reading the same forward and backward.

Thus, there are only 16 possible FIMs, 11 if the current limits of at most 3 consecutive bars or spaces are maintained.