> For the complete documentation index, see [llms.txt](https://guardian.hedera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guardian.hedera.com/docs/3.5.1/guardian/standard-registry/schemas/system-policy-schemas.md).
# Types of Schemas
There are four types of Schemas:
1. [System Schemas](#system-schemas)
2. [Policy Schemas](#policy-schemas)
3. [Tag Schemas](#tag-schemas)
4. [Module Schemas](#module-schemas)
To display System / Policy Schemas in the GUI, we have added a toggle in the Schemas tab.
## System Schemas
Whenever an account is created, System Schemas are generated automatically.
{% hint style="info" %}
Note: By default System Schemas cannot be edited/deleted.
{% endhint %}
## Policy Schemas
This is the second option in the Schemas tab. This option displays all the Policy Schemas related to all the created/imported Policies in the Policies tab.
The below screenshot shows the Policy Schemas of an imported Policy (i.e. iRec).
We also have a filter, where by default, all the Schemas of Policies are shown. We can also select a particular Policy to show the Schemas of the selected Policy.
## Tag Schemas
Tags can have attached/linked documents. To add a document to the tag a schema is required. Such documents can be found under the [**Tag Schemas**](/docs/3.5.1/guardian/standard-registry/schemas/tag-schema.md) section.
## Module Schemas
Module schemas needs to define minimum set of fields in module variable with type “schema”.
### Creation of Schemas
To create module schema, we need to click on Create New button:
### Using schemas:
Select module schema in “BaseSchema” field in module variables section
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://guardian.hedera.com/docs/3.5.1/guardian/standard-registry/schemas/system-policy-schemas.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.
.png)
%20(3)%20(2).png)
%20(9)%20(1).png)
.png)
.png)
.png)
.png)