Show unknown licenses in summary of results
"No license. All rights reserved" may be wrong, better display "No license found." or even better nothing at all
Problem to solve
If the license finder doesn't find a license, it displays "No license. All rights reserved". That may be wrong in many cases and additionally may give people the wrong impression.
Intended users
Every visitor of the project except for the maintainer/owner who sees "Add license" instead.
Further details
See for example https://salsa.debian.org/games-team/etw or https://gitlab.com/osgames/microwar which both have "No license. All rights reserved" although both have licenses, just not at the place where the license finder searches. The license finder is probably not perfect. If the license finder does not find a license, it should not assume that there is nothing to find. The website should not display information that it actually doesn't have. The truth is that then the license status is simply not known to the software.
"All rights reserved." doesn't need to be said really. "No license." is wrong.
Proposal
Depict what the state really is. Something along the lines of: "License detection failed. / No license could be detected. / No license found. / License status: unknown." or just nothing (which would be the best option IMHO).
Permissions and Security
Nothing special required.
Documentation
Couldn't find "No license" or "All rights reserved" in the documentation. Therefore nothing should be needed to change.
Testing
I don't see a risk
What does success look like, and how can we measure that?
The message will have changed.