Developers: what makes multiclient work?

I understand the mechanical process of modifying the executable for multiclient... (change english to something else, ..) But I was wondering - what precisely does this actually prevent from occurring? and why? I'm guessing it somehow makes conquer avoid checking for other instances, but then im wondering... How _DOES_ conquer check for other instances? Is it a shared memory segment, or what? I tested to see if it was using FindWindowA/W FindWindowExA/W etc.. and no attempt was ever made to locate another conquer as far as i know.

Any input?

It uses a mutex named TQ_CONQUER. But yeah, only if the client is English version so changing the string makes it skip the check.

edit: fixed mutex name