How do you label your units addresses on a quadplex? A,B,C,D?

[Sunny Burns]

So we are about to close on our first property and it is a quadplex. Its an REO, so can't really ask how they used to do it. The property is also a little unusual because it has two seperate duplexes on one lot, one in the front of the lot and one in the rear. On the deed the whole property is under 21 Irving Place, but when I called PSE&G they have the front as 21 and rear as 23. Is it okay to just label it as 23 even though its not written on the deed? On our side of the street it goes from 21 to 27, so it appears to be free to use... Anyway don't know if their are regulations for that.

So how do people normally do it? Currently I am thinking about these options:

-Apt A, Apt B, Apt C, Apt D

-Apt 1, Apt 2, Apt 3, Apt 4

-F1, F2, R1, R2

-A1, A2, B1, B2

-21A, 21B, 23A, 23B