Currently, Fedora uses "%doc" to mark license texts, but this is not optimal for many reasons. Some licenses require that the text of the license always accompany the software, even in scenarios where --nodocs would otherwise make sense.
I propose that the %license tag be created to handle license texts.
With this tag, we would now have a way to differentiate the license text from other documentation. This is important, because in Fedora, we are currently duplicating common license texts in multiple locations, simply to ensure compliance. It would be ideal if RPM contained logic along these lines:
1. Package marks license text as %license:
%doc README CHANGELOG
2. Upon installation, rpm looks in %_licensedir (customizable, but as a default suggestion, /usr/share/licenses/) to see if any identical files (identical to %license) are already present on the system.
3a. If an identical copy is already found in %_licensedir, do not install the license text (COPYING), but create it in %_defaultdocdir as a hardlink to the copy in %_licensedir.
3b. If an identical copy is not found in %licensedir, copy the license text to %_defaultdocdir.
That scenario would permit Fedora to create a "common-licenses" package that would be part of a default installation, and minimize the license footprint.