> For the complete documentation index, see [llms.txt](https://snowball-mns.gitbook.io/snowball/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://snowball-mns.gitbook.io/snowball/modular-naming-service-mns/identity-management-system/sub-identity.md).

# Sub-identity

Sub-identity within the MNS serves as a powerful mechanism for hierarchical identity management, customization, and personalization, and extending the functionality of MNS. 

<figure><img src="/files/vblTB4Zh9CU2TyV0Yrja" alt=""><figcaption></figcaption></figure>

User can freely add as many subidentities to their identity as they want, it is free of charge the only cost involves the gas fees to update the records on the resolver.

> @**sub-identity.identity**

Sub-identity is specified before the identity name with a "." as a separator. So if the identity is **@john** then subidentity will be added as **@sub-identity**.**john**.

<figure><img src="/files/HOwSe7E3HfzU4jB5zqj6" alt=""><figcaption></figcaption></figure>

This gives the ability for users to organize, manage, and interact with their identities in a flexible, secure, and efficient manner, supporting a wide range of use cases and scenarios in the decentralized identity space.