Document Unlicense compatibility issues?

[wking]

There's previous discussion of this in #33, #38, #61, #126, #496, docopt/docopt.rs#1, project-open-data/project-open-data.github.io#135, etc., but a number of projects have issues with the Unlicense, and it can lead to Unlicense code being judged incompatible (e.g. here). On the other hand, I expect there are also projects that would take issue with CC0's explicit lack of a patent grant (vs. the Unlicense's silence on patents). Is it worth working up wording around these issues? For example, pointing out concern about how the Unlicense's warrenty disclaimer interacts with its public-domain assertion? Or are these concerns rare enough that it's not worth bothering to mention them?

[mlinksva]

I don't know of anything that can be stated clearly and non-judgmentally. If there's an unconditional option that's less unambiguously problematic for software than CC0-1.0 and causes people to throw fewer hypothetical fits than Unlicense, happy to add it and maybe make more prominent. Related: #464 (comment)

Closing for now as I don't see any concrete action to take, though feel free to discuss or make a concrete suggestion.

[wking]

I don't know of anything that can be stated clearly and non-judgmentally.

We can point out that some projects have rejected Unlicensed code, pointing to cases like this one. That's doesn't mean we agree with those decisions, and we wouldn't be (directly) pointing out issues with the Unlicense. We'd just be pointing out that not everyone considers the Unlicense universally compatible (which may seem surprising to users interested in a public-domain dedication). On the other hand, the Docker folks have some code here which appears to be under the CC0. Wording could be a note addition along the lines of the first sentence in this paragraph, although more examples would be useful.