The ITU national point code is a 14-bit integer. The point codes can be a single number up to five digits, or two, three, or four numbers (members) separated by dashes.

If the ITU National Duplicate Point Code (ITUDUPPC) feature is on, ITU national point codes can have group codes assigned to them. The point code is a 1- to 5-digit number. The group code is a two-character field ranging from aa to zz that is entered as the last subfield of the point code and is separated by a dash from the rest of the point code. An example is 12345-az.

If the flexible point codes option is enabled (see the chg-stpopts command, :npcfmti parameter), an ITU national point code format consists of 2, 3, or 4 numbers separated by dashes (formatted as m1-m2-m3-m4). When the ITUDUPPC feature is also on, the format is m1-m2-m3-m4-gc with a group code. If one of the m1, m2, m3, m4 members is set to zero bits, no value is entered for that position in the point code. For example, if the npcfmti parameter value is set to 3-8-3-0, valid point codes would be 1-100-1-aa with a group code, or 7-255-7 with no group code. See the tables in the chg-stpopts command description for valid member values and additional examples.

The following ranges of values are valid:

• nnnnn016383
• nnnnn-gc0-16363; group code is aa-zz (the ITUDUPPC feature must be on)
• m1-m2-m3-m4Each member represents the number of bits allowed in the corresponding position for a flexible ITU national point code. The range of each member is from 0 - 14. Each member must be specified; the member value of 0 indicates that the position is not specified in the flexible point code. The sum of the member values must equal 14.
• m1-m2-m3-m4-gcEach member represents the number of bits allowed in the corresponding position for a flexible ITU national point code. The range of each member is from 0 to 14. Each member must be specified; the member value of 0 indicates that the position is not specified in the flexible point code. The sum of the member values must equal 14. Group code is aa-zz (the ITUDUPPC feature must be on).

An asterisk value (*) is allowed only for the rtrv-dstn and rtrv-rte commands to retrieve ITU-N DPCs if the ITUDUPPC feature is on (for point codes with group codes). The node and group code cannot both be *. For example, dpcn=12345-* and dpcn=*aa are allowed, but dpcn=*-* is not allowed.

If flexible point codes are also used, all valid m1, m2, m3, and m4 must all be either a number or an *. For example, 1-100-1-aa and *-*-*-aa are allowed, but 1-*-*-aa is not allowed.

ITU national point codes support the Spare Point Code subtype prefix (s-). The prefix can be specified before the point code subfield values to indicate a Spare Point Code (s-12345 or s-1-3-5-5-gc, for example). See Spare and Private Point Code Subtype Prefixes.