Identifiers

Grammar

Every independently addressable artifact has a stable ID matching:

<PREFIX>-<SEGMENT>(-<SEGMENT>)*
SEGMENT = [A-Z0-9]+

IDs are uppercase. The prefix is fixed per artifact type:

Prefix	Type
ACT-	Actor
JRN-	Journey
UC-	Use Case
BR-	Business Rule
TERM-	Domain Term
BC-	Bounded Context
FR-	Functional Requirement
QR-	Quality Requirement
CON-	Constraint
CHG-	Product Change
SLI-	Delivery Slice
HOF-	Product Handoff

An ID whose prefix does not match its artifact’s type is invalid. Authored IDs MUST be unique within one product repository across all artifact kinds.

Generated identifiers

HOF- is the one prefix whose IDs the tooling mints rather than a human authoring them. A Product Handoff ID is derived from the work-item reference it packages: HOF-<provider>-<work-item id>, uppercased.

That derivation does not guarantee uniqueness. One work item delivering more than one delivery slice produces one handoff per slice, all carrying the same ID, and nothing currently rejects it. The intended shape is one work item per slice, which keeps IDs unique; the gap and the candidate fixes are recorded as OD-009 in OPEN-DECISIONS.md. Consumers MUST NOT resolve a handoff by ID alone: evidence discovery matches on the handoff’s recorded source.product-change and source.delivery-slice, which are unambiguous.

IDs MAY be human-readable (ACT-PRODUCT-ENGINEER, FR-VALIDATE-001). Readability is encouraged but carries no semantics: tools MUST treat IDs as opaque.

Immutability

• An ID becomes immutable when the artifact is first accepted into the current product model (by the initial baseline or by promotion of a Product Change).
• An ID MUST never be reused, including after its artifact is retired or removed.
• The artifact’s title, file path, body and relationships MAY change; the ID MUST NOT.
• A Product Change that modifies an existing artifact MUST use the same ID in its proposed future-state artifact.

Identity is not location

Identity is defined by the id field only:

• IDs MUST NOT be inferred from file paths or file names.
• Moving or renaming an artifact file does not change its identity.
• References between artifacts MUST use IDs, never paths or titles.

File naming

An artifact’s file name SHOULD be its lowercase ID followed by .md (for example fr-validate-001.md for FR-VALIDATE-001). Validation MUST treat file-name misalignment as a warning (PRODUCT101), never as an error and never as an identity mechanism.