As for the anonymous accolade I still think Rebecca fits it well - she's named in a way, but purposefully unnamed in a specific way that the other characters are clearly defined - Maxim never calls her by her name even though he obviously knows it. I'd agree not to include Hero and Layer Cake though -they purposefully don't reveal their names in the same way Eastwood does in the Dollars trilogy or "Harmonica" does in OUATITW.
I hadn't thought about that sort of thing before you gave that example, but for me other characters avoiding a name is equivalent to the person hiding it — for this accolade, I just want films where it is only the film-makers who are avoiding it. A couple of times lately, I've watched the credits and only then realised that the name had never been mentioned — that's the sort of thing I'm going for.