Categories unique across projects?

Do category names for clientlibs need to be unique across all the projects on the same instance?

Say you have multiple sites hosted on the same AEM instance, each with its own apps folder.

apps/foo/text/clientlib

          category cat_text

apps/bar/text/clientlib

          category cat_text

What we found is that  foo page we ended up loading the css for both foo and bar projects.

If is easy enough to make each category unique, but it seems very wrong AEM would assume you'd want to take the styles from different app folders. Is that the how it's meant to work?

I don't seem to see the same issue where the clientlibs are in etc/clientlibs instead of the apps folder.