# Logical Record Architecture for Health and Social Care
## Discharge Summary Release 0.02

Contents
The content of this release is not comprehensive and is not fully validated and must not be used in live system implementations.
# Reference Model Class: II
As specified by ISO 21090, an identifier that uniquely identifies a thing or object. An identifier is designed to allow a person or system to select one record, object or thing from a set of candidates. To guarantee unambiguous identification the identifier must be globally unique. Instance identifiers, as specified by ISO 21090, are distinguished from concept descriptors in that the latter identify types and not individual things, although the former may sometimes be used to identify an individual record or object that represents the concept. Within some implementations some attributes which are called codes (e.g. NHS ODS job role code and NHS Data Dictionary and Model ORGANISATION CODE) actually identify instances and are therefore represented by instance identifiers and not concept descriptors. ## Specializes ## ANY ## Attributes
Name | Data type | Occurs | Description
--- | --- | --- | ---
root | Uid | 0..1 | As specified by ISO 21090, a unique identifier that guarantees the global uniqueness of the instance identifier. This root may be either a DCE UUID (represented in upper case), an Object Identifier (OID), or a special identifier taken from lists that may be published by ISO or HL7. The root attribute ensures global computational uniqueness and may indicate the identification scheme to which the extension attribute (if present) must conform (e.g. NHS Number, UK Driver Number, etc). However, receivers must not attempt to infer the identity of the organisational entity (or entities) that manages the issuing of an identifier conforming to the scheme (e.g. NHS in England and Wales, UK Driver and Vehicle Licensing Agency, etc). Nor should they be used to infer the type of thing identified (e.g. patient, driver, etc). This is because a number of different organisations may manage the the assigment of identifiers belonging to a given scheme and that such authority may transfer from organisation to organisation over time while the scheme remains the same. Within the LRA, role types are specified using a separate type attribute.
extension | BusinessId | 0..1 | A character string as a unique identifier within the scope of the identifier root as specified by ISO 21090 and constrained within the LRA to type BusinessId. The root scheme and the scheme specific extension together create a globally unique identifier for the item that this II value identifies.
identifierName | String | 0..1 | As specified by ISO 21090, a human-readable name for the scheme represented by the root.
displayable | Boolean | 0..1 | As specified by ISO 21090, true if the identifier is intended for human display and data entry otherwise false, e.g. used only for machine interoperation.
scope | IdentifierScope | 0..1 | As specified by ISO 21090, the scope in which the identifier applies to the object with which it is associated.
reliability | IdentifierReliability | 0..1 | As specified by ISO 21090, the reliability with which this identifier is known. This attribute may be used to assist with identifier matching algorithms.
## Constraints
Type | Name | Specification
--- | --- | ---
no displayable if null | Invariant | inv: isNull implies displayable.oclIsUndefined
no extension if null | Invariant | inv: isNull implies extension.oclIsUndefined
no identifierName if null | Invariant | inv: isNull implies identifierName.oclIsUndefined
no reliability if null | Invariant | inv: isNull implies reliability.oclIsUndefined
no root if null | Invariant | inv: isNull implies root.oclIsUndefined
root is required | Invariant | inv: isNotNull implies root.oclIsDefined -- nullFlavor invariants