it just says that the UC schools are asking you to fill out their application and that its not a substitute for AMCAS blah blah blah...same UC email as the others basically plus it says
***FOR UC IRVINE, COLLEGE OF MEDICINE (ONLY UCI-COM!), WE ASK THAT YOU RETURN YOUR UC APPLICATION WITH A SELF-ADDRESSED STAMPED POSTCARD FOR US TO RETURN TO YOU ACKNOWLEDGING THE RECEIPT OF THE INITIAL APPLICATION.