In New York City, these tags are embedded into the asphalt and communicate useful information about local infrastructure, and who's done the work.

Most importantly, the 5-digit number along the outer ring of the asphat tag denotes the permit holder, the contractor responsible for work above or below the streets. The number at the center indicates the year that the work was done.

The color indicates the agency the work was done for - Plumbing is green, signal and street light work is orange, Verizon is red, Con Ed is blue, MTA is purple, and so on.