---
modificationDate: May 24, 2021
title: Expo Structured Field Values
description: Version 0
---

<AgentInstructions>

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</AgentInstructions>

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# Expo Structured Field Values

Version 0

Structured Field Values for HTTP, [IETF RFC 8941](https://tools.ietf.org/html/rfc8941), is a proposal to formalize header syntax and facilitate nested data.

Since it is still a work in progress, Expo maintains a custom version that only implements the following subset of the protocol defined in [IETF RFC 8941](https://tools.ietf.org/html/rfc8941):

-   All key values
-   String, integer, and decimal items
-   Dictionaries