Noop
From Scriptwiki
Noop is a command that does literally nothing and doesn't care about any parameters.
/noop
What is it good for, then?
It is a handy command when you need to evaluate some identifier without using the actual result. For example, you may want to evaluate a $regex identifier without using the information how many results it returns, just to later use the back-references it creates. Another example is $findfile which has a command option in itself, and therefore doesn't need any outside commands to handle its results.
Examples
For example:
noop $regex(I have 6 brothers,/I have (\d+) brothers/) | echo -ag The number of brothers is $regml(1)
Note: This command came in mirc 6.17, for older versions .echo -qg would be the same thing (the dot to make it silent and -q not to show it, if it was silent), or you could even use //.xyzzy ;).