-devel rpm question

[Kaleb S. KEITHLEY]

When adding a new sub-package, what's the convention or rule regarding 
the associated -devel?

E.g. for glusterfs, with its associated glusterfs-devel; when adding 
glusterfs-api containing a new library, should the .so link and header 
be in glusterfs-api-devel, or can they be in the glusterfs-devel rpm?

It (obviously) occurs to me that having glusterfs-devel install the .so 
link and header file for a library that may not be installed would 
probably be frowned upon.

(Yes, I've read 
http://fedoraproject.org/wiki/Packaging:Guidelines#Devel_Packages)

Thanks

-- 

Kaleb