====== Controlled Vocabulary ======

[[public:99_annexes:annex-b-terms-and-definitions:start|Go up to Terms and Definitions]]

===== Discussion =====

A Controlled Vocabulary defines a governed set of terms or values used within a specified scope. It promotes consistent meaning, validation, interoperability, and automated processing by limiting the terms or values that may represent a concept.

Each entry in a Controlled Vocabulary may include:

  * A stable identifier or code
  * A preferred label
  * A definition
  * Alternative labels
  * A scope note
  * A status
  * An effective period
  * A source
  * A version
  * Relationships to other entries

A Controlled Vocabulary may be **closed** or **extensible**.

A closed Controlled Vocabulary permits only the entries identified by the applicable vocabulary version. An extensible Controlled Vocabulary permits adding new entries through an established governance process. Extensibility does not permit an implementation to introduce arbitrary values without authorization.

A Controlled Vocabulary is distinct from its implementation representation. For example, an implementation may represent the entries using an enumeration, a code list, strings, numeric codes, or Uniform Resource Identifiers. The implementation representation preserves the identity and meaning of the vocabulary entries.

A Controlled Vocabulary does not necessarily define hierarchical or logical relationships among its entries. A taxonomy adds hierarchical relationships, while an ontology may define formal concepts, relationships, constraints, and axioms.

===== Definition =====

>//defined set of terms or values whose use and meaning are governed within a specified scope//

===== Source =====

Adapted from:

  * [[https://www.w3.org/TR/skos-reference/|W3C Recommendation: SKOS Simple Knowledge Organization System Reference]], retrieved 2026-10-08
  * [[https://www.iso.org/standard/53657.html|ISO 25964-1:2011, Information and documentation — Thesauri and interoperability with other vocabularies — Part 1: Thesauri for information retrieval]], retrieved 2026-10-08

===== Note =====

  * A Controlled Vocabulary identifies the authority responsible for governing its entries
  * Each entry is distinguishable from every other entry in the same vocabulary
  * A stable identifier should be assigned when systems reference an entry independently of its label
  * A label may change without changing the identity of the vocabulary entry
  * Version, status, and effective-period information support changes to the vocabulary over time
  * The vocabulary definition identifies whether the vocabulary is closed or extensible
  * A value outside a closed Controlled Vocabulary is not conformant
  * A Controlled Vocabulary is not necessarily a taxonomy or ontology
  * A platform-independent Controlled Vocabulary does not prescribe its programming language, schema, database, or serialization representation
  * An implementation mapping preserves the identity and meaning of each vocabulary entry

===== Example =====

The FX Information Model defines a closed [[public:99_annexes:annex-b-terms-and-definitions:p:party_kind|Party Kind]] Controlled Vocabulary containing the following entries:

^ Vocabulary Entry ^ Meaning ^
| [[public:99_annexes:annex-b-terms-and-definitions:p:person|Person]] | An individual human being |
| [[public:99_annexes:annex-b-terms-and-definitions:o:organization|Organization]] | An organized body or group having a common purpose |

Because this Controlled Vocabulary is closed, an implementation cannot introduce `Counterparty`, `Financial Institution`, or `Legal Entity` as additional Party Kind values.

`Counterparty` identifies a Role, `Financial Institution` identifies an Organization Classification, and `Legal Entity Recognition` records jurisdiction-dependent legal recognition. These concepts remain distinct from Party Kind.

A platform-specific implementation may represent the Controlled Vocabulary as an enumeration:

<code>
enum PartyKind {
    PERSON,
    ORGANIZATION
}
</code>

The enumeration implements the Controlled Vocabulary. It is not the authoritative definition of the vocabulary or its entries.

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