Non-denominated

Non-denominated stamps are exactly that and have been around for much longer than US Forever stamps have been. It has now become common for many postal systems to use them.

One of the earliest was the Austrian newspaper stamp of 1874 (see below). In the later 1940s, due to runaway inflation, the Republic of China issued specific issues or surcharged stamps for various services like domestic regular mail, domestic registered mail, etc. in their Unit stamp scheme.  File:Austria Newspaper A A.webp|1874 Austria newspaper stamp. File:GB WW airpost.A.webp|modern Great Britain international rate airmail stamp. 