| url | No | uri | Canonical identifier for this code system, represented as a URI (globally unique) (Coding.system) |
| identifier | No | Identifier[] | Additional identifier for the code system (business identifier) |
| version | No | string | Business version of the code system (Coding.version) |
| name | No | string | Name for this code system (computer friendly) |
| title | No | string | Name for this code system (human friendly) |
| status | Yes | code | draft / active / retired / unknown |
| experimental | No | boolean | For testing purposes, not real usage |
| date | No | dateTime | Date last changed |
| publisher | No | string | Name of the publisher (organization or individual) |
| contact | No | ContactDetail[] | Contact details for the publisher |
| description | No | markdown | Natural language description of the code system |
| useContext | No | UsageContext[] | The context that the content is intended to support |
| jurisdiction | No | CodeableConcept[] | Intended jurisdiction for code system (if applicable) |
| purpose | No | markdown | Why this code system is defined |
| copyright | No | markdown | Use and/or publishing restrictions |
| caseSensitive | No | boolean | If code comparison is case sensitive |
| valueSet | No | canonical | Canonical reference to the value set with entire code system |
| hierarchyMeaning | No | code | grouped-by / is-a / part-of / classified-with |
| compositional | No | boolean | If code system defines a compositional grammar |
| versionNeeded | No | boolean | If definitions are not stable |
| content | Yes | code | not-present / example / fragment / complete / supplement |
| supplements | No | canonical | Canonical URL of Code System this adds designations and properties to |
| count | No | unsignedInt | Total concepts in the code system |
| filter | No | CodeSystemFilter | Filter that can be used in a value set |
| - id | No | string | Unique id for inter-element referencing |
| - extension | No | Extension[] | Additional content defined by implementations |
| - modifierExtension | No | Extension[] | Extensions that cannot be ignored even if unrecognized |
| - code | Yes | code | Code that identifies the filter |
| - description | No | string | How or why the filter is used |
| - operator | Yes | code[] | = / is-a / descendent-of / is-not-a / regex / in / not-in / generalizes / exists |
| - value | Yes | string | What to use for the value |
| property | No | CodeSystemProperty | Additional information supplied about each concept |
| - id | No | string | Unique id for inter-element referencing |
| - extension | No | Extension[] | Additional content defined by implementations |
| - modifierExtension | No | Extension[] | Extensions that cannot be ignored even if unrecognized |
| - code | Yes | code | Identifies the property on the concepts, and when referred to in operations |
| - uri | No | uri | Formal identifier for the property |
| - description | No | string | Why the property is defined, and/or what it conveys |
| - type | Yes | code | code / Coding / string / integer / boolean / dateTime / decimal |
| concept | No | CodeSystemConcept | Concepts in the code system |
| - id | No | string | Unique id for inter-element referencing |
| - extension | No | Extension[] | Additional content defined by implementations |
| - modifierExtension | No | Extension[] | Extensions that cannot be ignored even if unrecognized |
| - code | Yes | code | Code that identifies concept |
| - display | No | string | Text to display to the user |
| - definition | No | string | Formal definition |
| - designation | No | CodeSystemConceptDesignation | Additional representations for the concept |
| - id | No | string | Unique id for inter-element referencing |
| - extension | No | Extension[] | Additional content defined by implementations |
| - modifierExtension | No | Extension[] | Extensions that cannot be ignored even if unrecognized |
| - language | No | code | Human language of the designation |
| - use | No | Coding | Details how this designation would be used |
| - value | Yes | string | The text value for this designation |
| - property | No | CodeSystemConceptProperty | Property value for the concept |
| - id | No | string | Unique id for inter-element referencing |
| - extension | No | Extension[] | Additional content defined by implementations |
| - modifierExtension | No | Extension[] | Extensions that cannot be ignored even if unrecognized |
| - code | Yes | code | Reference to CodeSystem.property.code |
| - value[x] | Yes | code, Coding, string, integer, boolean, dateTime, decimal | Value of the property for this concept |
| - concept | No | [] | Child Concepts (is-a/contains/categorizes) |
