To my knowledge, the only planet that can be completed 100% is Hutta (32/32). And that's for a bounty hunter; no idea if it works for other Imperial classes. On my Sentinel main I have 594/738 so far with AT LEAST 60-70 bugged/unobtainable entries. Would be really, really nice if Bioware would come out and tell us in a comprehensive list what is in-game and what's unavailable currently. They don't have to tell us where/how to get them, just whether or not they can be obtained right now. They seem to be dragging their feet on fixing the codicies (and yes I get that it's low priority; especially since they just now deleted everyone's matrix cubes and can't figure out how to return them).