Feature summary (what you would like to be able to do and where):
Currently, users have the option to "Enter a different license in wikitext format" when the license is not among the choices allowed.

It is proposed to amend the label to "Enter a different license or public domain tag in wikitext format" (emphasis added to highlight the change, not to be replicated in the final message).

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
This would encompass all the cases in which the user indicates a public domain tag that is not among the ones that are already indicated in the other options.

Benefits (why should this be implemented?):
It would clarify to users that they can also add public domain tags (that are not licenses, but mere declarations of public domain), and not just licenses.