I've just installed rxvt from pkgsrc and found it's missing 
some features I want, like Xdefaults support.

Where should I look to find the docs for customizing a 
package built from pkgsrc, and the specifics for 
customizing rxvt?

I think it should be as simple as setting some values in 
/etc/mk.conf, and doing a "make deinstall reinstall" but 
I don't know where to find the values.  

I've spend some time searching and digging around the 
NetBSD site, but I haven't found anything applicable yet.

I appreciate any help.  Thanks!