First of all, some options don’t take an argument at all. In the Clon
jargon, these options are called flags. Flags just stand for
themselves: either they are present on the command-line, or they are not
(as a matter of fact, this is a lie, see Option Retrieval). A
typical example of a flag would be displayed like this in a standard
help string (but see Output):
-h, --help Print this help and exit.