The Times covers issues related to lobbyist access in New York in this article.

No one seems to know for sure exactly when the protocol was established, but it is fairly straightforward: Lobbyists wishing to speak to a lawmaker are supposed to go to the east entrance, give their business cards to a sergeant-at-arms and identify the Assembly member they wish to see. The sergeant will then try to find the requested member on the floor and hand him or her the card.

But the more knowing lobbyists head to the back hall — about the length of half a city block, with gleaming white marble floors and walls, a vaulted ceiling and Romanesque archways — which teems with Assembly members and their staff on any given session day.