Their lawyers names. How simple is that?
No, seriously. Walk through a criminal courthouse in a suit and at least ten different people will stop you and say "Do you know who my lawyer is?" My favorite response is, "I don't know who you are, how would I know who your lawyer is?"
And it's not that hard. Get their card. Bring it with you when you're going to court. Sounds simple to me.
And, here's another thing - the names of your other lawyers. You've got an immigration lawyer? A family court lawyer working on your child support issue? A lawyer for your other criminal case, in another jurisdiction? A parole lawyer? Give me their phone numbers! Or, I'd settle for just their names, so I can look up their numbers.
Oh, and, just a hint: "I know it's a lady," or "I know it's a dude," is not equivalent to knowing your lawyer.