If you live on 6th St in Emery what syntax do you use?

Hey,

I "live" in Emery on 6th St with a couple thousand like minded folks.

John Doe
411 N 6th St #1234
Emery, SD 57332-2124

Well, went to a web site to enter my address, and the # symbol was not allowed.

I used "pmb" but was thinking of using "Unit" or just deleting the symbol altogether.

What do you do or recommend?