OWFa

 OWFa  is an abbreviation for Open Web Foundation Agreement and is an open license for providing a (Royalty Free) RF patent declaration, e.g. for a standards specification.

OWFa 1.0 is the latest version.

Criticism
Bruce Perens comments on the all-or-nothing approach of OWFa:

"[Perens] points out that there’s a proviso in section 8.6 that deems implementations of [the specification] as compliant “so long as all required portions of the Specification are implemented.” In other words, if you find something in the specification that you don’t need for your implementation and you leave it out, you’ve also lost your license to use the spec."

From.