---
title: "custom field · RUAL Documentation"
description: "checks if the given custom field exists in a document."
canonical: https://docs.rual.nl/block-types/query/query_bool_exists_custom
language: en
---

# custom field

This block is part of the [`query`](https://docs.rual.nl/block-types/query) group and was last modified in core [`v10.4.28`](https://docs.rual.nl/core-versions/100428).

### Parent Requirements

This block requires specific parent elements: `query_bool_must`, `query_bool_must_not`, `query_bool_filter`, `query_bool_should`, `query_first_defined`. Ensure this block is placed within the appropriate parent context.

checks if the given custom field exists in a document.

### Core Releases