The Data Module Code (DMC)

Each data module has a unique and complex identifier. The DMC is used to manage data modules in the CSDB, retrieve them, or access them in an electronic environment. The DMC, together with the metadata in the identification and status section described above, allows the chunks of information to be independently managed and reused. The illustrations or multimedia objects associated with the data modules have a similar code.

The DMC’s structure is standardized, even though the lengths of its individual components may vary. (The DMC can be anywhere from 17 to 41 alphanumeric characters.) 

The table below shows the breakdown of a DMC identifier into its component parts. 



Hardware identification


Model identification code

2 to 14 alphanumeric characters

System difference code (SDC)

1 to 4 alphanumeric characters

Standard numbering system (SNS)

6 or 8 alphanumeric characters*


              2 alphanumeric characters


              1 alphanumeric character


              1 alphanumeric character

            Unit or assembly

              2 or 4 alphanumeric characters

*  There may be an additional optional Material Item Category Code (MICC) character as the first character

Disassembly code (DC)

2 alphanumeric characters

Disassembly code variant (DCV)

1 to 3 alphanumeric characters (no hyphen before)

Information type


Information code (IC)

3 alphanumeric characters

Information code variant (ICV)

1 alphanumeric character (no hyphen before)

Item location code (ILC)

1 alphanumeric character

Except as noted, the characters for the elements are separated by hyphens, so the result is:

(minimum) YY - Y - YY-YY-YY - YYY - YYYY - Y


Standard Numbering System (SNS)

The SNS consists of four segments: system, subsystem, sub-subsystem, and unit/assembly. These segments identify the equipment breakdown. The SNS identifies a particular system, subsystem, component/assembly, or part of the system or equipment.

A standardized method of assignment for commodity types of components/items is normally established by the requiring authority (e.g., technical publications community). These standardized assignments make it easier for the user in the field to cross-reference between different TMs of equipment maintained by that organization.

The SNS breaks down the level of detail on a given project for which a particular data module or publication holds information. An SNS identifier makes up part of the Data Module Code (DMC) for every data module.



For additional details on how project information decisions are made and applied, consider registering for one of our training courses.