This made me wonder what the shortest open source license is, and it seems to be the Fair License: https://en.wikipedia.org/wiki/Fair_License

> <Copyright Information>

>

> Usage of the works is permitted provided that this instrument is retained with the works, so that any entity that uses the works is notified of this instrument.

>

> DISCLAIMER: THE WORKS ARE WITHOUT WARRANTY.

EDIT: I would not use this license. I'm not sure how this got approved by the OSI, but I'm not a lawyer. Some of the email threads think the disclaimer is insufficient, and I'm not entirely sure that it confers all the expected rights since it only says "Usage" (copying, modification, distribution).