Naming of a .pc file: package.pc vs package-version.pc

[Thomas Moulard]

Hello,
I was wondering if anyone could suggest me what is the best way to
name a ``.pc'' file.
On my system I have some packages using the package-version.pc naming
(like bonobo-activation-2.0.pc)
or the package.pc naming (like cairo.pc).

I was wondering if there is some kind of rule.

More specifically: what is the more robust way to name pkg-config
files to avoid problems when having
several versions of a library installed on a system.
The PKG_CONFIG_PATH variable mechanism seems dangerous in that case.

Any suggestion?
Thanks,
-- 
Thomas Moulard