Check out LD 90 you can ALOW or DENY numbers under SPN,NPA, NXX
ALOW x...x Allowed codes for ADM/MDM to be recognized within
the NXX, NPA or SPN
The maximum number of digits to be entered must be
the lesser of 10 or:
• 7-m (8-m for 1 + dialing) for NXX
• 10-m (11-m for 1 + dialing) for NPA
• 19-m for SPN
Where: m = number of digits entered for NPA, NXX, or
SPN.
These numbers do not have to be leftwise unique. For
non leftwise unique numbers, the longer number takes
precedence over the shorter number. However, the
exact same numbers (not leftwise unique and the same
length) are still blocked.
basic-22
DENY x...x Number to be denied within the NPA,NXX,SPN, or
SDR.
The maximum number of digits to be entered must be
the lesser of 10 or:
• 7-m (8-m for 1 + dialing) for NXX
• 10-m (11-m for 1 + dialing) for NPA
• 19-m for SPN
Where: m = number of digits entered for NPA, NXX, or
SPN.
These numbers do not have to be leftwise unique. For
non leftwise unique numbers, the longer number takes
precedence over the shorter number. However, the
exact same numbers (not leftwise unique and the same
length) are still blocked.
b/nars-1