control: snd_ctl_open(): which names are acceptable?

Hello Alsa developers,

I'm currently enhancing the libalsa API documentation. In the process, I try to understand how each API function works and what the underlying concepts are.

The snd_ctl_open() call takes a name, which is a C string (const char*). For my sound card, the names "hw:CARD=PCH" and as well as "hw:2" (2 is the card index) worked.

Which strings are acceptable as name? Are there maybe even more formats? Is there some documentation on this?

Regards, Tanjeff