[clamav-users] Are signatures for Windows only?

[J.R.]

I keep thinking about this from time to time, but keep forgetting to
post before I get sidetracked doing something else...

Are the ClamAV default signature files geared towards Windows
executables / malware / documents / (generic spam)? Or do they cover
other platforms as well?

Reason I'm asking, I've seen an increasing amount of people posting
about their non-windows platforms that are scanning their *entire*
system, and I'm wondering if it is just a waste of CPU cycles, or if
there are actual signatures that could detect anything on those
platforms (that are not windows related)?