---
title: What is the “Label (key)” field for?
description: "For input and choice components, the **Label (key)** (or “name”) is the **key** under which the value is sent in the flow response (e.g. `screen_0_name_0`). It is derived from the label (lowercase, spaces to underscores) but you can edit it.…"
url: "https://www.smsgatewaycenter.com/blog/kb/what-is-the-label-key-field-for/"
updated: "2026-07-16"
category: WhatsApp Business API / WhatsApp Flows
---

# What is the “Label (key)” field for?

For input and choice components, the **Label (key)** (or “name”) is the **key** under which the value is sent in the flow response (e.g. `screen_0_name_0`). It is derived from the label (lowercase, spaces to underscores) but you can edit it. Use a short, unique key (e.g. `email`, `appointment_date`). Meta has a limit (e.g. 64 characters) for this key.

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