> For the complete documentation index, see [llms.txt](https://help.aristotlemetadata.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.aristotlemetadata.com/registration-authorities/creating-and-editing-registration-authorities/validation-rules/setting-validation-rules.md).
# Setting validation rules
{% hint style="info" %}
Registration Authority validation rules can only be written and assigned by Registration Authority Managers and Registrars, or Registry Administrators.
Registry-wide validation rules can only be written and assigned by Registry Administrators.
{% endhint %}
Validation Rules allow Registration Authority Managers and Registrars to set business rules for metadata within their Registration Authority, or allow Registry Administrators to set registry-wide rules for all content.
Validation Rules can be used to specify:
* Mandatory fields
* Uniqueness of fields
* Length of fields
* Formats of names.
### How to assign a validation rule to a Registration Authority
1. Select 'Browse' from the registry header.
2. Select the icon for 'Registration Authorities', or 'Browse' beneath it.
3. Select the Registration Authority you wish to write a validation rule for.
4. Select the 'Settings' tab.
5. Select 'Validation Rules'.
6. [Write your desired validation rule(s)](/registration-authorities/creating-and-editing-registration-authorities/validation-rules/setting-validation-rules/writing-validation-rules.md) into the 'Rules' field, then select 'Submit'.
### How to assign a registry-wide validation rule
1. Select 'Administrator tools' from the dashboard side panel.
2. Select 'Manage Registry Validation Rules'.
3. [Write your desired validation rule(s)](/registration-authorities/creating-and-editing-registration-authorities/validation-rules/setting-validation-rules/writing-validation-rules.md) into the 'Rules' field, then select 'Submit'.
