RC-8090 is essentially the office code for IRCC HQ. They're the first to look at your app and then decide if it's complete and send you your AOR. They also process all if not most of all out of country applications in collaboration with the different international imm./visa offices (which also are RC****). So during if you see that it typically means an office domestic or int'l has sent/requested something from them. What you may be referring to is the batch/officer code assigned to your app, at the local level, which is different, typically has initials like XX****, YY****.Mine is also assigned to rc-8090