+.B nmh
+command arguments are usually called
+.IR switches .
+Some switches have a corresponding \*(lq\-no\*(rq switch, which
+negates all previous occurrences of that switch on the command line.
+This allows a user to conveniently override, on the command line, a
+switch in their profile. Switches may be abbreviated as long as there
+is no ambiguity with another switch of the same command. To avoid
+ambiguity with any switches that may be added in the future, it is
+recommended that full switch names be used in durable code such as
+shell scripts, functions, and aliases.
+.PP