A lot of times people who write macros have lots of comments and instructions in the text of the macro. I'd like to propose a way of showing those comments within a SAS session. This would especially be handy when the original code file isn't available or convenient.
%help to run foobar, supply a, a date field, and b, a numeric field: %foobar(a=bdate,b=anum). This will return something wonderful;
(body of macro)
So, in SAS you could run %foobar /help or %foobar(help) (or something like that); and it would display the help message.