If one of the built-in options is almost what you need, you may be
tempted to subclass it directly instead of using defoption, and
only change what’s needed, After all, it’s Lisp. Lisp is a world of
mess^D^D^D^Dfreedom.
Wrong.
defoption is not only a convenience wrapper around
defclass. It also arranges for defsynopsis and
defgroup to recognize your new option type. So please, do use it
systematically.