B is for Bisect

Bisect stamp with a scissors
Bisect Cinderella Stamp

A postage stamp cut in half and used to pay half of its face value. In the early decades of stamps, senders resorted to this practice when they lacked postage of the required denomination. For collecting purposes, a cancellation must "tie" the bisect to the envelope to prove that the stamp was actually used to send mail. Otherwise, any cancelled stamp could be cut in half and passed off as a bisect.

10c Victor Emmanuel II vertical bisect on folded letter
10c Victor Emmanuel II vertical bisect

Mailed from Ascoli on December 30 or 31, 1860, this letter arrived at Macerata on January 1, 1861. This envelope is a very rare use of a bisect to pay a rate that was short-lived in this territory. Sardinia, 1860.