[ThenAsNow]

We probably need better, consistent terminology for different types of "not all the freedoms of open source but not proprietary secret source either", the way "open source" means something very specific.

The Wikipedia page you cited opens with "Source-available software is software released through a source code distribution model that includes arrangements where the source can be viewed, and in some cases modified, but without necessarily meeting the criteria to be called open-source."

So by this definition, "source available" is a superset of FOSS, but not specific enough to imply what the user can and can't do with the source code. It makes sense to name classes of license within the "source available" umbrella that spell out what freedoms are restricted/preserved.

The Big Time license is not specific as to whether the covered software is provided in source or binary form, and is easily applied to source code distributions. Probably the reason I associated this license with "source available" is the primary license author is a prominent U.S. lawyer involved with open source and I'm pretty confident it is written to be applicable to source code even if it is not explicit about it. Similarly, the BSD license doesn't require that the license be attached to source code - one could release binary-only software under the BSD license.