To answer my own question, from the Baltimore Sun:
(looks like we're bringing three peanut butter and jelly sandwiches for the kid, lol).
YOU CAN BRING: Small tote-style umbrellas, (2) plastic factory-sealed water bottles or an empty reusable water bottle, small digital/disposable cameras, small blankets or beach towels, kid supplies when accompanying a child (i.e. stroller, kiddie food), sunglasses/hats/sunscreen, a valid photo ID to drink
YOU CAN'T BRING: Framed/large backpacks, knives/weapons, chains or chain wallets, chairs of any kind, outside food, coolers, tents or large umbrellas, video cameras, audio recording devices, professional cameras (changeable lenses), pets, drugs/paraphernalia, laser pointers