c. Tactical numbering plan Tactical units use a seven-digit numbering plan.
= primary zone
= switch location
= subscriber's number
We use the following numbers:
(1) The PR-SL plan is a 3/4 numbering plan. In Appendix B, there is a list of tactical PR codes
developed jointly for use around the world.
(2) The MYX codes are to be used by a DSN subscriber to access the tactical subscriber when
activated by Defense Information System Agency (DISA). These MYX codes are essentially the area
codes for the tactical network.
3. Tactical circuit switch (CS) switchboard numbering plans. This paragraph discusses the numbering
plans available for the several CS/switchboards used.
a. AN/TTC-39/39A CS numbering plan. We can program the AN/TTC-39 and AN/TTC-39A to
support three distinct numbering plans. They are as follows:
PR-SL-XXX (7 digits)
NYX-NNX-XXXX (10 digits)
9YX-MYX-NNX-XXXX (13 digits)
b. AN/TTC-38 CS numbering plan. We can program the AN/TTC-38 to support the general
tactical numbering plan.
72-98, except 80, 81, 90 and 91
0.000 Restricted for operator
DC closure lines
Trunks to automatic switches, manual switchboards, or local subscribers