HPND (Historical Permission Notice and Disclaimer)
The catch-all name for the old, home-grown permission notices that universities and companies wrote before MIT and BSD became the default.
In the 1980s and 90s many copyright holders drafted their own short text: permission to use, copy, modify and distribute without fee, provided the notice is kept, plus a warranty disclaimer. Often there was also a ban on using the author's name in advertising. The OSI approved HPND as a historical category so such code would not sit in a grey zone.
SPDX now lists a long tail of variants with suffixes naming where each text came from, because nearly every institution phrased things slightly differently. The result is license proliferation in fossil form: perfectly harmless, but tedious for anyone classifying every file in an old source tree.