---
title: "warning · RUAL Documentation"
description: "background in warning style"
canonical: https://docs.rual.nl/block-types/ui class/uiclass_background_warning
language: en
---

# warning

This block is part of the [`ui class`](https://docs.rual.nl/block-types/ui%20class) group and was last modified in core [`v10.4.28`](https://docs.rual.nl/core-versions/100428).

background in warning style

- uiclass `uiclass`

A typical wiring for [warning](https://docs.rual.nl/block-types/ui%20class/uiclass_background_warning): the `uiclass` out pin feeds [regular card](https://docs.rual.nl/block-types/state%20ui/state_card).

![Studio canvas example for the warning block: typical wiring for warning.](https://docs.rual.nl/canvas-examples/uiclass_background_warning.png)

### Version history

Introduced in [`v10.4.28`](https://docs.rual.nl/core-versions/100428).