A semi-postal stamp or semipostal stamp is a philatelic term for a postage stamp issued to raising money for some purpose, usually for charity.[1] Semi-postals have an additional monetary value (surcharge), devoted to that specific non-postal, charitable purpose and separated from the official postal value with a "+" sign.[2]
↑"Semipostal". Glossary of Stamp Collecting Terms. AskPhil; Collectors Club of Chicago. Archived from the original on 2012-04-12. Retrieved 2009-08-22.