rc.conf when ssid has spaces in it: missing documentation or missing feature?

[Yuri]

I can't find any references in rc.conf(5) on how to set up ifconfig line 
if SSID has spaces which is very typical situation.
ifconfig(8) doesn't mention this either but it works if I put quotes 
around it.

I would assume spaces should be substituted for '_' like in Linux. But I 
remember I wasn't able to make it work for some reason.

Yuri