> For the complete documentation index, see [llms.txt](https://docs.acpt.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.acpt.io/meta-fields/the-meta-fields-manager/validation-rules-fields-settings.md).

# Validation rules fields settings

How to use the validation rules

Click the "**Add Rule**" button. A new rule row appears.

<figure><img src="https://3235524095-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fiyf0tSKPgXiyoQ3zV3I6%2Fuploads%2Fgit-blob-99638fd5f5f0b80b7145e328dbe5376e6d70a8b8%2Fmeta-validation-rules.png?alt=media" alt=""><figcaption></figcaption></figure>

A validation rule has several inputs:

* **The operator**
* **The value**
* **The error message**

Let's see in detail.

### **The operator**

The allowed options are:

* **equals to**
* **is not equal to**
* **is less than**
* **is greater than**
* **is less than or equal to**
* **is greater than or equal to**
* **is empty**
* **is not empty**

### **The value**

If the operator **is not**:

* **is empty**
* **is not empty**

the value field is required.

The value can be numeric or string.

### **The error message**

Every validation rule needs an error message.

When the operator changes, the error message default value will change consequently.

The placeholder string `{{v}}` represents the input value, and should not be touched.

### Basic example

Suppose you have a number field and want to force its value to be greater than 30.

In case of the input validation fails, the error message will be:

```
Value is lower than or equal to 30
```