Being the fourth in a series of articles looking at the old Who's Who series' collection of entries and imagining how many entries would make up a new DC reference work before and after the Flushpoint.
Looking at who's around in the New52 alphabetically between Ca- and Chro-, Chemical Kid can take the Chem King's spot and Captain K'rot Carrot's, though we can of course also include the Cadmus Project, Captain Steel (down one issue from Commander), Cat Grant, Centipede, Chase, Chameleon Girl, Choke, Capucine, and the Children of Zeus. Catgirl is likely still in continuity via Batman Inc. That's so few, I feel like I'm probably forgetting someone.
All but very few of the New52 additions would also have made it in a series about the unrebooted DCU, in addition to Checkmate, a different Cain (David Cain), the Candlemaker, Carnivora, Carapax, Catalyst, Catherine Cobert (she hasn't been forgotten, right?), Cerberus, Chas Chandler, Captain Stingaree (robbed of his spot in the original Who's Who), Cardinal Sin, Cassandra Craft, Catspaw, Catgirl, Carcharo, Charlie Vickers (the forgotten Earth Green Lantern), Charma, Chiller, Chimera, Chris Kent, the Captains of Industry, the Chain Gang, the Champions of Angor, the Children of Ares, the Cathexis, and additional versions of the Cavalier, Captain Boomerang and the Challengers of the Unknown. How about Central City? I'd love to see DC's fictional cities get some entries.
But you know me, I wouldn't really be happy until I saw Calorie Queen, Cary Bates as himself, and Captains Action, Thunder and Strong no matter how obscure or outside continuity they are! One thing looks certain, the "C"s must be back-loaded because the front half is thin indeed.