You can place comments in a description file by preceding them with a number sign (#):
# Comment on line by itself
OPTIONS = /MAP # Comment on macro's line
all.exe : one.obj two.obj # Comment on dependency line
link $(OPTIONS) one.obj two.obj;
A comment extends to the end of the line in which it appears. Command lines (and dependency lines containing commands) cannot contain comments.
To specify a literal #, precede it with a caret (^), as in the following:
DEF=^#define #Macro representing a C preprocessing directive