Package freedom verification problems
This page lists some situations when a package looks nonfree but is free and can be included in Parabola.
1 Packages including nonfree licenses can be multi-licensed
Many packages are dual licensed under a common free and a less common nonfree one. In this case only the nonfree license is included with the package.
It's possible that all code licensed under this license can be used under the free one so the package is free.
Example: Perl (any version of GNU GPL or Artistic License 1.0)
2 No modification allowed for "works of opinion" or "non-functional data"
FSDG allows including data not for practical use licensed without allowing modifying it. However, it doesn't allow including data which cannot be used/distributed commercially. Other distributions like Debian require all data to comply with the same requirements as software, so they don't accept non-modifiable data.
Explicitly stating that a data package is removed due to disallowing commercial distribution makes it clear that it's not removed due to this difference.
Examples: any GNU FDL-licensed manual with cover text or invariant section, data of some games
3 Selling allowed only with other software
It's not a problem if the user is allowed to e.g. sell the package with a copy of GNU Emacs attached.
Examples: any SIL OFL licensed package, Beneath a Steel sky.