|Mandatory||Repeatable||Data Type||Authority||Level Available||A/V Only||Public Element|
|No||No||Variable Character Length (30)||None||Series
The identifier that a NARA custodial unit specifies to be used to request archival materials in the unit's custody.
|Purpose:||The local identifier allows researchers to request, and the custodial unit to retrieve, archival materials.|
|Relationship:||This element is independent.|
Enter exactly the identifier that the NARA custodial unit specifies for researchers to use to request materials. Custodial units that use Local Identifier may have developed a unit-wide numbering system. Use this element if your unit has such a system. Units should strive to keep the identifiers unique within the unit, but should be aware that other NARA units may use the same numbering system.
The National Archives Identifier (NAID) serves as the Reference Code and should be used as the unique identifier. The NAID is used consistently across all custodial units.
Custodial units may use agency-assigned identifiers, Master Location Register numbers, inventory entry numbers, or other identifiers not created by the custodial unit in this field as long as the unit has determined that this is the identifier by which they want users to request the material. Those identifiers should also be placed in Variant Control Number. If a local identifier changes, the old identifier should be placed in Variant Control Number, with the Variant Control Number Type "Former Local Identifier."
Do not include notes or explanations in this element. Do not include mail codes in the local identifiers. Mail codes can change over time due to reorganizations.