Yes I definitely could do that if its ME who makes 2.mrc
But lets say I don't have "control" over the contents of 2.mrc ?

Say I make complex script and want to make sure that if user adds scripts to it they will go through my "validator" script first for example. To check whether its aliases wont conflict with existing ones, that it will be loaded into specific position, etc... (Just an example).

echo -a $signature