[Fontconfig] Keywords for specifying sans, serif etc

[Sairus Patel]

I can't find FontConfig documentation that describes how exactly a client can request a default sans, sans serif, or monospaced font. That is, there are no special FontConfig "keywords" for these. I grepped the 2.8.0 source code and couldn't find anything corresponding to these keywords or similar.

So, is it simply up to the person who sets up the config files as to what keywords should be used ("sans-serif", "sans_serif", "sans", "_sans", etc)?

(I tried searching the archives but didn't find anything conclusive. Apologies in advance if I missed something.)

Best,
Sairus