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Appendix C


In developing an obstacle plan, a uniform numbering system is used to identify obstacles. This numbering system is used with maps, lists, obstacle overlays, and annexes. A recommended numbering system with an example follows:

Unit Designation

Unit Type

Target Number




The unit designation identifies the division or corps (or other separate command) that authorized the target. Examples are:

2XXX - II Corps

23XX - 23d Division

The unit type is a letter that identifies the type or branch of the designated unit. A corps target has no letter designation. The following code is used for unit type:

A - Armor

C - Calvary

H - Airmobile

I - Infantry

M - Mechanized

P - Airborne

Examples are:

2XXX - II Corps

23XXA - 23d Armored Division

82XXP - 82d Airborne Division

The target number is a three-or four-digit number assigned by the unit to a particular target. Corps and division break down blocks of numbers to subordinate units. Corps uses target numbers 001 through 999. The division number system is:

Division uses target numbers 0001 to 0999

1st Brigade uses target numbers 1001 to 1999

2d Brigade uses target numbers 2001 to 2999

3d Brigade uses target numbers 3001 to 3999

(NOTE: Further subdivision of brigade number blocks is not permitted.)

Target numbers 4000 through 9999 may be assigned to divisional units as required, or to other units operating in the division's area of responsibility. Examples are:

2XXX0157 - II Corps, target number 157

23XXA1021 - 1st Brigade, 23d Armored Division, target number 1021

It is not necessary to use the complete target number on a division or brigade obstacle overlay. Within a particular unit, the unit designation and type are dropped. Instead of 23XXA0784, the number 0784 is used. For obstacles authorized or ordered by other units within the same overlay, the full target number must be used. The number 2XXX0023 would be a II Corps target.

If necessary to distinguish them, denial targets are given a suffix "D" such as 2XXX0057-D.

It is a serious mistake to add any of the following as part of the obstacle number. These "add-ons" rapidly reduce the system to unworkability.

  • Further symbols.
  • Subordinate number block assignments.
  • Additional information such as status, target-type location, preparing unit, and relation to a supply facility.

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