What This Field Means
The principal retained source supporting the unit’s identity in this record.
This connects the unit record to the principal retained evidence used to establish its identity or central claims. It gives maintainers a direct route back to the source that justified creating or accepting the record.
How to Read It Correctly
Primary Evidence is not necessarily the only source, the newest source, or the source for every field. A unit may require several records to establish name, status, lineage, location, and command relationships.
Example
An official roster, lineage history, order, fact sheet, or historical publication.
Technical Specification
The database column is [USMIL-Unit].[Unit].[PrimaryEvidenceID]. Required foreign key to the primary Evidence record. Additional evidence may exist, so this field is an anchor rather than a complete source list.
The value is required and must point to an existing Evidence record. Choose the strongest retained item for the record’s core identity and keep additional supporting or conflicting evidence separately rather than discarding it.
| Property | Definition or current value |
|---|---|
| Database column | PrimaryEvidenceID |
| Column order | 52 |
| SQL data type | bigint |
| Kind of information | Foreign-key relationship |
| Cardinality | One stored value per Unit row. |
| Required | Yes |
| Database default | No database default |
| Key or relationship | Foreign key to USMIL-Ontology.Evidence.SourceEvidenceID |
| Database check constraint | ([CurrentStatus]=N'Planned' OR [CurrentStatus]=N'Status unknown' OR [CurrentStatus]=N'Historical' OR [CurrentStatus]=N'Inactive' OR [CurrentStatus]=N'Current') |
| Live population | 9341 of 9341 Unit records (100%) |
| Distinct nonblank values in the live table | 3323 |
| Live profile measured | September 2, 2026, 20:43 UTC |
Allowed Values and Definitions
No preset menu applies to this field. It stores an identifier, relationship, measurement, date, timestamp, or evidence-derived narrative. Valid content is governed by the SQL type, key relationship, nullability, retained evidence, and the field-specific recording rule above. A list of observed contents would be data, not a list of allowed options.
Missing, Unknown, and Conflicting Information
This column cannot be NULL in the Unit table. When the underlying fact is incomplete, the record must use an allowed explicit disposition or a supported evidence-derived statement. Required storage does not mean that every historical fact is known, and it never authorizes a guessed value.
Connections to Other Fields
- Evidence Authority — Why the supporting source is considered reliable enough to establish or describe the unit.
- Unit Confidence — How certain the guide is that the unit identity and its major claims are correct.
- Authorization Document — The official order, directive, roster, law, or other record that supports the unit’s creation or recognition.
- Official Unit Designation — The unit’s full official name or designation as supported by military records.
- Lineage Continuity — What the evidence says about whether two names or organizations belong to the same official lineage.