Code: BIN (official violation code)
Description: Building Identification Number - Every building in NYC is assigned a unique 7-digit BIN by the Department of Buildings. It is used to track all DOB records for that building.
Practical Meaning: The BIN that is assigned to a building is never changed (except to correct assignment errors); it remains assigned to that building permanently, even if the building is subsequently demolished or its borough, block and lot number changes as a result of a tax lot merger or apportionment. If a building is demolished, and a new building is subsequently built and given the same address as that of the demolished building, NYC assigns to the new building a new BIN, different from that of the demolished building. In this case, the same address ambiguously identifies two distinct buildings (the new one and the demolished one), but each building is unambiguously identified by its own unique BIN.
Source: BIN locator