---
title: system
framework: healthkit
role: symbol
role_heading: Instance Property
path: healthkit/hkclinicalcoding/system
---

# system

The string that identifies the coding system that defines this clinical code.

## Declaration

```swift
var system: String { get }
```

## Discussion

Discussion The system is usually expressed as a URL from the HL7 Terminology. For example, the RxNorm, a coding system for medications uses: http://www.nlm.nih.gov/research/umls/rxnorm.