Sec.  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  Sec. 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]