Dear Larry,

I am looking for a way to link scientific publications to 
ebuilds/packages. The easiest, but hacky way right now is to use the 
|<doc lang="doi">https://doi.org/...</doc>|. Integration with 
|epkginfo|/|equery meta| works nicely out of the box. However, currently 
|pkgcheck| and/or the XML format complains about repeated |lang| entries 
and does not allow long |lang| attributes (i.e. |lang="inspirehep"| 
fails understandably).

You can inspect a detailed example here 
https://github.com/gentoo/sci/pull/1216.

The more sophisticated way, instead of abusing the |lang| attribute, 
would be another attribute, perhaps |reference|, or a new element in 
|upstream| instead of |doc|. Before I move forward with this idea, I 
would be curious to hear your thoughts on it.

Best,
APN