What This Field Means
The branch of the U.S. Armed Forces to which the unit belongs, or whether it is joint.
This tells readers which U.S. Armed Force owns or constitutes the organization, or that the organization is genuinely joint. It is one of the most useful filters for helping veterans narrow a search.
How to Read It Correctly
Service affiliation is not force component, departmental oversight, operational command, or participation in a joint mission. An Army unit under a joint commander remains an Army unit unless the organization itself is joint.
Example
Army, Navy, Marine Corps, Air Force, Space Force, Coast Guard, or Joint.
Technical Specification
The database column is [USMIL-Unit].[Unit].[ArmedService]. Required service-affiliation summary. A formal controlled vocabulary exists, but the current scalar field includes several legacy joint or exclusion expressions.
Use the controlled Armed Service vocabulary when the evidence supports it. Qualified legacy phrases found in the current scalar column are data variation, not permission to create new service branches.
| Property | Definition or current value |
|---|---|
| Database column | ArmedService |
| Column order | 14 |
| SQL data type | nvarchar(128) |
| Kind of information | Ontology-controlled classification with a scalar Unit-table summary |
| Cardinality | Unit table: one scalar summary per row. Ontology dimension: multiple; time-varying: true. |
| Required | Yes |
| Database default | No database default |
| Key or relationship | None |
| 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 | 10 |
| Live profile measured | September 2, 2026, 20:43 UTC |
Allowed Values and Definitions
The complete active controlled vocabulary is listed below. The ontology is authoritative for normalized options. Narrative or legacy phrases found in the scalar Unit-table column are current data expressions, not additional approved options.
| Ontology property | Definition |
|---|---|
| Ontology dimension | Armed service |
| Dimension number | 7 |
| Ontology definition | Army, Navy, Marine Corps, Air Force, Space Force, Coast Guard, or none or joint. |
| Ontology cardinality | multiple |
| Changes over time | Yes |
| Active controlled options | 12 |
| Canonical option | Code | Plain-language definition | Technical definition |
|---|---|---|---|
| Unknown | unknown | The evidence reviewed so far does not establish a value. | No supported value is asserted; this is an evidentiary state, not a positive classification. |
| Not applicable | not-applicable | This question does not apply to this kind of unit or relationship. | The dimension is intentionally inapplicable to the subject type; it is not missing data. |
| Unresolved | unresolved | The unit is known, but the available evidence does not yet settle this particular point. | Confirms that resolution remains open after review without asserting a competing value. |
| Needs review | needs-review | The retained evidence needs additional review before a reliable value can be shown. | Places the assertion in a review-required disposition rather than accepting a substantive value. |
| Source conflict | source-conflict | Reliable sources disagree, so the guide preserves the disagreement instead of choosing one silently. | Records an unresolved conflict among retained sources and prevents false canonical certainty. |
| Army | army | Army identifies an organization constituted within the United States Army. | Controlled armed-service code 'army' in ontology Dimension 7. It records constitutional service affiliation independently of component, departmental oversight, or temporary joint employment. |
| Navy | navy | Navy identifies an organization constituted within the United States Navy. | Controlled armed-service code 'navy' in ontology Dimension 7. It records constitutional service affiliation independently of component, departmental oversight, or temporary joint employment. |
| Marine Corps | marine-corps | Marine Corps identifies an organization constituted within the United States Marine Corps. | Controlled armed-service code 'marine-corps' in ontology Dimension 7. It records constitutional service affiliation independently of component, departmental oversight, or temporary joint employment. |
| Air Force | air-force | Air Force identifies an organization constituted within the United States Air Force. | Controlled armed-service code 'air-force' in ontology Dimension 7. It records constitutional service affiliation independently of component, departmental oversight, or temporary joint employment. |
| Space Force | space-force | Space Force identifies an organization constituted within the United States Space Force. | Controlled armed-service code 'space-force' in ontology Dimension 7. It records constitutional service affiliation independently of component, departmental oversight, or temporary joint employment. |
| Coast Guard | coast-guard | Coast Guard identifies an organization constituted within the United States Coast Guard. | Controlled armed-service code 'coast-guard' in ontology Dimension 7. It records constitutional service affiliation independently of component, departmental oversight, or temporary joint employment. |
| Joint / none | joint-none | Joint / none applies when the organization is genuinely joint or when exclusive affiliation with a single armed service does not apply. | Controlled armed-service code 'joint-none' in ontology Dimension 7. It records constitutional service affiliation independently of component, departmental oversight, or temporary joint employment. |
How the Live Unit Table Uses This Field
All 10 distinct nonblank expressions currently stored in the scalar Unit-table column are shown below.
| Observed live expression | Live Unit records |
|---|---|
| Navy | 3601 |
| Army | 2164 |
| Air Force | 1522 |
| Marine Corps | 1409 |
| Joint | 366 |
| Coast Guard | 212 |
| Space Force | 58 |
| Joint / department-level | 5 |
| No U.S. armed service | 3 |
| Joint force | 1 |
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.
The controlled uncertainty values are deliberately different: Unknown means evidence has not established a value; Unresolved means the question remains open after review; Needs review identifies work still requiring evaluation; Source conflict preserves disagreement among retained sources; and Not applicable means the dimension does not apply to the subject.
Connections to Other Fields
- Force Component — Whether the unit belongs to the regular force, Reserve, National Guard, or another supported component.
- Service Unit System — The service-specific organizational system in which the unit’s type and level make sense.
- Administrative Command — The service-side organization responsible for administration, readiness, personnel, training, and support.
- Operational Command — The command directing or employing the unit for an operation, deployment, exercise, or assigned mission.
- Organization Class — The broad institutional form of the organization, such as a command, school, center, company, or defense agency.