The $MESSAGE directive allows to insert user-defined Warning, Hint or Note. It is equivalent to one of the $FATAL, $ERROR, $WARNING, $HINT or $NOTE directives. It must be followed by one of the words ERROR WARNING HINT or NOTE, and then the message to display, as follows:
{$MESSAGE WARNING This was coded on a rainy day by Bugs Bunny}
This will display a warning message when the compiler encounters it. The effect is the same as the {$WARNING} directive.
This means that the following:
{$MESSAGE WARNING Coded on a rainy day}
{$MESSAGE NOTE Coded on a very very rainy day}
{$MESSAGE HINT Coded on a very rainy day}
{$MESSAGE ERROR This is wrong}
{$MESSAGE FATAL This is so wrong, the compiler will stop at once}
is completely equivalent to
{$WARNING Coded on a rainy day}
{$NOTE Coded on a very very rainy day}
{$HINT Coded on a very rainy day}
{$ERROR This is wrong}
{$FATAL This is so wrong, the compiler will stop at once}
Note that if the -Sew switch is used, the WARNING message will be treated as an error, and the compiler will stop.