What do all the zoning symbols, such as r2 or m3, mean?

Zoning symbols vary among communities. An R2 zone in one community is not necessarily the same as an R2 in another community. Frequently, communities use letters of the alphabet as code abbreviations to identify the use allowed in a physical geographic area, such as A for agricultural (or airport or apartments), R for residential, C for commercial, I or M (industrial or manufacturing) and P for park or parking lots. These symbols are usually followed by a number to specify the level of use; for example, the common generalizations are R1 for a single-family home, R2 for two-dwelling units, R3 for a apartment complexes, and so forth.

Some communities may also designate another number to indicate certain square footage for that particular zone, as for example, R1-3 to signify a single-family dwelling with a lot size of less than 3 acres.