The PLC would be the Platoon Leaders Class that the Marine Corps offers to kids during the summer while they are in college, kind of a pipeline into OCS. I myself am just going straight into OCS with my bachelors degree, hoping to go the aviation path as well, but there seems to be nobody who knows much of anything about the version of the ASTB that Marines take, if there are any differences at all. Like do we take the whole thing, do our scores matter, is it pass/fail, etc. Nobody seems to know exactly.