N.Y.C. Admin. Code § 28-502.2: § 28-502.2 Registration of outdoor advertising companies.

On and after a date to be provided by rule, it shall be unlawful for an outdoor advertising company to engage in the outdoor advertising business or, by way of advertising, promotions or other methods, hold itself out as engaging in the outdoor advertising business unless such company is registered in accordance with this code and the rules of the department. Such rules shall establish a procedure pursuant to which the department may require the single registration of an outdoor advertising company and its affiliates. An outdoor advertising company and its affiliates made subject to single registration shall be considered a single outdoor advertising company for purposes of this code.