Non-denominated postage

Non-denominated postage is postage intended to meet a certain postage rate that retains full validity for that intended postage rate even after the rate is increased. It does not show a monetary value, or denomination, on the face. In many English-speaking countries, it is called non-value indicator (NVI) postage. Invented to reduce the cost of printing large issues of low-value stamps to "top-up" old issues, NVI stamps are used worldwide, including in the United States and some European countries.

UPU approval

The Universal Postal Union approved the use of non-denominated stamps on international mail in 1995.

Canada

Canada's NVI was called the "Permanent" stamp, which is a trademarked term. It was originally marked by a white capital "P" overlaid on a red maple leaf, which is itself within a white circle. Later releases, such as the 2009 Silver Dart commemorative, varied the colours. In that example, the Maple Leaf around the "P" is white and the "P" is dropped out. The circle does not appear.