This will toggle off and on the messages dealing with a certain type of
command.   The possible message types are "aliases", "actions", "substitutes",
"antisubstitutes", "highlights", "variables", "pathdir", "read", and "delimiter".
This is very helpful if you are using #math and #if, and setting a lot of
variables, so you don't keep getting the Variable Set messages.
example:
#message {variable}
toggles whether messages dealing with variables will be shown.
#message {variable} {1}
toggles it to be TRUE.