question about default site file

I'm writing a little tool that our clients will execute to configure their freeradius instance (given a stock - nothing changed yet setup). Basically it parses the various setup files and makes substitutions, changes, etc. The idea here is the client won't (shouldn't) edit the files manually. Anyway I noticed that the files ship with sql module directives with a prefixed dash. Ie. -sql What's the meaning of this? Couldn't find it documented anywhere. Another comment method? Something else? Bill