Permanent Stamp (Canada Post)

The Permanent stamp is Canada Post's non-denominated domestic-rate stamp, marked with a letter P in a maple leaf instead of a value. It went on sale on November 16, 2006 at the then domestic rate of 51 cents, with Flag definitives as the first designs, and remains valid for a domestic letter after rate increases, removing the need for top-up stamps.

Text from OyList