§  52.7   Definitions.

   As used in this subpart:

   (a) Area code or numbering plan area (NPA). The term "area code or
   numbering plan area" refers to the first three digits (NXX) of a
   ten-digit telephone number in the form NXX-NXX-XXXX, where N represents
   any one of the numbers 2 through 9 and X represents any one of the
   numbers 0 through 9.

   (b) Area code relief. The term "area code relief" refers to the process
   by which central office codes are made available when there are few or
   no unassigned central office codes remaining in an existing area code
   and a new area code is introduced. Area code relief includes planning
   for area code "jeopardy," which is a situation where central office
   codes may become exhausted before an area code relief plan can be
   implemented.

   (c) Central office (CO) code. The term "central office code" refers to
   the second three digits (NXX) of a ten-digit telephone number in the
   form NXX-NXX-XXXX, where N represents any one of the numbers 2 through
   9 and X represents any one of the numbers 0 through 9.

   (d) Central office (CO) code administrator. The term "central office
   code administrator" refers to the entity or entities responsible for
   managing central office codes in each area code.

   (e) North American Numbering Plan Administrator (NANPA). The term
   "North American Numbering Plan Administrator" refers to the entity or
   entities responsible for managing the NANP.

   (f) Billing and Collection Agent. The term "Billing & Collection Agent"
   ("B&C Agent") refers to the entity responsible for the collection of
   funds to support numbering administration for telecommunications
   services from the United States telecommunications industry and NANP
   member countries.

   (g) Pooling Administrator (PA). The term "Pooling Administrator" refers
   to the entity or entities responsible for administering a
   thousands-block number pool.

   (h) Contamination. Contamination occurs when at least one telephone
   number within a block of telephone numbers is not available for
   assignment to end users or customers. For purposes of this provision, a
   telephone number is "not available for assignment" if it is classified
   as administrative, aging, assigned, intermediate, or reserved as
   defined in § 52.15(f)(1).

   (i) Donation. The term "donation" refers to the process by which
   carriers are required to contribute telephone numbers to a
   thousands-block number pool.

   (j) Inventory. The term "inventory" refers to all telephone numbers
   distributed, assigned or allocated:

   (1) To a service provider; or

   (2) To a pooling administrator for the purpose of establishing or
   maintaining a thousands-block number pool.

   [ 61 FR 47353 , Sept. 6, 1996, as amended at  62 FR 55180 , Oct. 23, 1997;
    65 FR 37707 , June 16, 2000]