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
SB-	Structured Behaviour
CHG-	Product Change

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.

CHG-INITIAL is reserved for the single initialisation change (see Product Changes → Initialisation). The SLI- and HOF- prefixes are retired and MUST NOT be reused (RFC 0004).

Authored identifiers

All IDs are authored by humans (possibly assisted by AI) and accepted into the model by a reviewed merge. No prefix is tool-minted in v0.2. IDs MAY be human-readable (ACT-PRODUCT-ENGINEER, FR-VALIDATE-001, SB-CANCEL-PAID-ORDER, CHG-CITATIONS-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 Product Definition: applied by a Product Change and merged into the canonical branch.
• 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 revision that modifies an existing artifact MUST keep the same ID.

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.