# 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: PQR
This class represents physical quantities that cannot be represented in UCUM unit, but are expressed using a concept in a standard terminology. The codingRationale attribute appears to be defined twice in the draft text of ISO 21090, but is not present as part of this class in the LRA, nor do we believe it is part of ISO 21090 â€" this looks like a documentation error in 21090. ## Specializes ## PQV ## Attributes
Name | Data type | Occurs | Description
--- | --- | --- | ---
unit | CD.CV | 1..1 | This is implemented as described in ISO 21090.
## Constraints
Type | Name | Specification
--- | --- | ---
no codingRationale in LRA | LRA Invariant | inv: codingRationale.oclIsUndefined
no originalText | Invariant | inv: originalText.oclIsUndefined
no source | Invariant | inv: source.isNull
no updateMode or History on PQR | Invariant | inv: noUpdateOrHistory
null or value | Invariant | inv: isNull xor value.oclIsDefined