This is the set of resources that conform to either of the profiles SimpleQuantity (http://hl7.org/fhir/StructureDefinition/SimpleQuantity) and SimpleQuantity (http://hl7.org/fhir/StructureDefinition/SimpleQuantity). E.g. what you have to deal with if you get resources conforming to one of them
| Name | Flags | Card. | Type | Description & Constraints    Filter:   | 
|---|---|---|---|---|
|   Quantity | C | 0..* | A fixed quantity (no comparator) Constraints: qty-3, sqty-1 | |
|    extension | 0..* | Extension | Additional content defined by implementations | |
|    value | Σ | 0..1 | decimal | Numerical value (with implicit precision) | 
|    unit | Σ | 0..1 | string | Unit representation | 
|    system | Σ | 0..1 | uri | System that defines coded unit form | 
|    code | Σ | 0..1 | code | Coded form of the unit | 
|  Documentation for this format | ||||