Would it be useful to have a default license for the Zotero Style Repository
specify some licenses in CSL? This will make it easier later on to sort on certain license types.
<link rel="rights" href="http://creativecommons.org/licenses/by-sa/3.0/us/"/>
BTW, should it be allowed at all to use certain more restrictive licenses?
all styles have a lot in common, and it is often impossible to tell which style served as a basis for a certain other style.
You can create a style without basing it on another, though.