Whenever I see New York City parking signs, I’m always reminded of this Futurama quote:

“Tour Guide: I direct your attention to this ancient and mysterious tablet which has yet to be deciphered.

[He points to a parking sign. Leela turns to Fry.]

Leela: Do you know what it means?

Fry: Yeah, I asked a cop once. It means “Up yours, kid”.”

The parking signs are indeed mysterious: for instance does 7am-7pm refer to unauthorized vehicles? One thing I can tell you – DOITT means Department of Information Technology and Telecommunications and probably refers to which NYC government fiefdom is allowed to park on that street.