I agree this makes sense. The help text is the primary output of the program in this case, so it should be stdout. (However, if you want longer documentation th

I agree this makes sense. The help text is the primary output of the program in this case, so it should be stdout. (However, if you want longer documentation then a man page might be better anyways.) You would use stderr for status messages, error messages, and other stuff that is not the primary output of the program. (In some cases, this might include help text; like another comment says, if you specified wrong arguments (not --help) then a short description might be a part of the error message.) One program that does write error messages to stdout and that annoys me significantly is Ghostscript. (Although you can tell it to write it to stderr, doing that causes all output to be written to stderr; I want output from "print", "==", etc to be written to stdout.)