PS: /set %a $+ b 1 is complete nonsense too.
Actually.. it's not. It sets %ab to 1. You'll find that mIRC does NOT evaluate the first parameter of:
/set
/unset
/var
/inc
/dec
ScatMan was wondering why /sockread isn't included in that list, given that the first parameter has the same purpose as in /set. I wonder about /bset ..