Block / Code Status
US (NANPA: AS/AV/RT) and Canada (CNA: AS/AV/AF/AP/…), read separately · also called assigned, available, retained, AS, AV, RT, AF, AP
The administrative state of a prefix or block in the numbering records — assigned, available or retained — read separately for the US (NANPA) and Canada (CNA), whose status sets differ.
Every central-office code and thousands-block carries an administrative status in the numbering records. The status sets differ between the United States and Canada, and the same letters do not always carry the same meaning — so they are best read country by country.
United States (NANPA reports). The common thousands-block statuses are AS (assigned to a service provider), AV (available in the shared pool), and RT (retained by the original carrier and not returned to the pool).
Canada (CNA records). In Canadian thousands-block records, AF means Available (Future) — available for assignment, but with a future effective date. AP means Available (Pending) — available for assignment, pending verification of PSTN activation by the CO Code holder. AS means Assigned — assigned by the CNA to a service provider. AF and AP are conditional available states; neither should be treated as Assigned (AS).
In both countries these statuses describe the allocation of a numbering resource, not how many individual numbers within it are in service.
"Assigned" is an allocation status, not a usage measure. An assigned block can be nearly empty of active subscribers; status describes who holds the resource, not how full it is. And an available status with a qualifier — Canada's AF (future) or AP (pending) — is not the same as assigned.
Every area code page on NumberResearch shows this in practice — assigned prefixes, thousands-block breakdown and exhaust forecast. For example: area code 626 ↗.