---
type: "datatype"
title: "string"
datatype: "string"
---
# string

- [Datatypes](/datatypes)
- [Definitions](/datatypes-definitions#string)
- [Examples](/datatypes-examples#string)
- [Mappings](/datatypes-mappings#string)
- [Profiles](/datatypes-profiles#string)

## Primitive Details
- **Definition**: A sequence of Unicode characters
- **Comments**: Note that FHIR strings SHALL NOT exceed 1,048,576 (1024*1024) characters in size
- **XML Schema/Base**: `string`
- **JSON Type**: `string`
- **Regex**: `^[\s\S]+$`
- **Characteristics**: has-length
- **v3 Mapping**: `ST`
- **v2 Mapping**: `ST`