N.Y. Comp. Codes R. & Regs. tit. 17, § 150.1
(e) Blank sign means an outdoor advertising sign void of advertising or informative content. An “available for lease” or similar message that concerns the availability of the sign itself shall not constitute advertising matter. A sign whose message has been partially obliterated by the owner so as not to identify a particular product, service or facility, or a sign which advertises an event which is outdated by more than 30 days, shall be treated as a blank sign. An outdoor advertising sign containing a public service message may be recognized as advertising matter provided the following criteria are met:
(g) Certified controlled area means a zoned commercial or industrial area for which the State has certified to the Federal Highway Administrator, pursuant to the provisions of the agreement entered into between the Commissioner of Transportation and the Secretary of Transportation of the United States, dated May 13, 1968, that there has been established within such area regulations, which are enforced, with respect to the size, lighting and spacing of outdoor advertising signs.
(h) Conforming sign.
A sign that is lawfully erected and maintained in a zoned or unzoned commercial or industrial area that complies with the requirements of sections 150.6, 150.7 and 150.8 of this Part.
(i) Commercial or industrial activity for purposes of an unzoned commercial or industrial area means any activity generally recognized as commercial or industrial by zoning authorities in this State, except that none of the following activities shall be considered commercial or industrial:
(aa) Nonconforming sign means a sign that is located in a controlled area, that was lawfully erected under State law and is lawfully maintained but which does not comply with the provisions of the outdoor advertising control statutes or such section as amended or the regulations promulgated pursuant to such statutes enacted or promulgated subsequent to the date of erection or which sign fails to comply with such statutes or regulations due to changed conditions.
(bb) Nonconforming grandfathered sign.
A sign lawfully in existence as of June 1, 1968 in a commercial or industrial area that does not comply with the size, spacing and lighting criteria of this Part, which is allowed to remain at its existing location for the duration of its normal life subject to customary maintenance.
(hh) Public service sign means a sign located on a school bus stop shelter, which sign:
The following words and phrases used in this Part are defined as follows: