I want to know if ADCOMS contact other ADCOMS
I am not sure, but I would venture and say yes. I know my one of my good friends is really close to the dean of admissions at his law school and he says they are constantly trading applicants during the admission season, i.e. the dean from Harvard will call Stanford and say "gablaze23 is a really strong candidate and we really want him and we know that squali83 applied to you as well and has great credentials, but we feel he will be a better fit at Stanford as opposed to here. So in interest of our yield, why don't you reject gablaze and we will reject squali so everyone is happy." As crappy as that sounds, I understand it is not unusual to have something like that transpire.