# obligatory stamp

> stamps that must be affixed to all mail at certain times for various reasons (support after disasters, as a form of war tax, etc.); usually only on domestic letters, etc.

**Wikidata**: [Q11643336](https://www.wikidata.org/wiki/Q11643336)  
**Source**: https://4ort.xyz/entity/obligatory-stamp


## References

1. Großes Lexikon der Philatelie (2 ed.)
2. Integrated Authority File