http://home.comcast.net/~crudfactory/fontfig-patch.2009.08.17.21.25.06.diff
This patch turns off recognition of Preferred Family and Style, changes precedences, and maybe does a few more things that I don’t remember. This is to work around bugs in GIMP and maybe still in Inkscape and other programs. These programs otherwise are totally broken if you, for instance, collect such fonts as Adobe Opticals.
I’m not making any bug reports, because I’m too used to getting the runaround on font-related issues.
(There may be side effects on other programs, due to the precendence changes.)