[FUBAR-BDHR]

What do they actually do and what do they work with?  Did a search and the only stuff I could find was from 2004. 

[karajorma]

I've not used them at all. I think they're somewhat neglected because scripting can do much of what they can do anyway.

Unless the wiki says which gauges each SEXP works with I'm without a clue which ones can actually be changed. The code gives no indication at all.