Hi SarahJane
Generally the As Bs etc refer to what type of property can be built on the land.
For example 2 A in most places tends to be freestanding homes and subdivisions that allow free standing homes on battleaxes etc.
2 B on the other hand means Duplex, and restricted townhouse development.
2 C may mean multi storey unit dwellinges etc.
Approach you local council for a zoning sheet., tha will explain it for you.
ta
rolf