some licenses are rather long and thus it could be easily detected
whether their "License" paragraph in debian/copyright is too short to
possibly contain them.
Here some examples of licenses which are probably long enough such that
this heuristic would have a low amount of false positives but are not
shipped in /usr/share/common-licenses:
- AGPL3
- LaTeX Project Public License
- Python Software Foundation License
- Mozilla Public License
- Creative Commons licenses
the user would then get a message like: "your License stanza for AGPL3+
is only 20 lines long and thus probably not the full text of the AGPL"