Some postage or revenue stamps did not have an inscription indicating their intended use, and they were unofficially used for both purposes.
Most British colonies issued stamps bearing inscriptions such as "Postage & Revenue" between the late 19th and early 20th centuries, and some countries such as Ceylon overprinted existing stocks of postage stamps with that inscription.
[7] In some cases, the issue of dual-purpose stamps created problems regarding the division of income between the post office and the treasury.
[2] Some colonies such as Malta and Natal switched a number of times between having separate and dual-purpose issues.
[7] A few current or former British colonies such as Montserrat and Nevis continue to issue dual-purpose stamps in the early 21st century.