o The listing level count allows macros to be listed
selectively; a macro definition can specify .NOSHOW at the
beginning to decrement the listing count and can specify .SHOW
at the end to restore the listing count to its original value.
o The alternate forms of .SHOW and .NOSHOW are .LIST and .NLIST.
o The initial setting for each .LIST/.SHOW option (except
BINARY) is obtained from the command-line setting using the
/SHOW qualifier.
o The /[NO]SHOW=BINARY option overrides the .[NO]SHOW BINARY
directive.