This seems like a great case for solid comments in the code, as long as they're up-to-date and you don't have a huge number of permutations. I know we all like

This seems like a great case for solid comments in the code, as long as they're up-to-date and you don't have a huge number of permutations. I know we all like to crap on code comments here, but if you had say 5 possible permutations that this code supported, a programmer could easily throw a comment above it with each of the supported functions, comma-separated. Then grepping would indeed find them.