# Modifying the Schema

Each document of the Editor conforms to a specific [schema](http://prosemirror.net/docs/ref/#model.Document_Schema) which describes the [nodes](http://prosemirror.net/docs/ref/#model.NodeSpec) and the [marks](https://prosemirror.net/docs/ref/#model.MarkSpec) that the document may contain.

The nodes conform to the HTML elements such as paragraphs, headings, lists, tables, images, and so on. The marks conform to the inline formatting options such as Bold, Italic, FontSize, and so on. By modifying the default, built-in schema, you can add additional types of nodes and marks as well as edit and remove the existing ones.

## Modifying the Default Schema

The following example demonstrates how to:

* Add a new node to nodes object of the schema.
* Add a new mark to marks object of the schema.
* Add a custom attribute to the existing nodes.

[Demo Source](https://demos.telerik.com/kendo-vue-ui/editor/schema-edit/source.txt)

## Creating Custom Schema

The following example demonstrates how to implement a custom Editor schema.

[Demo Source](https://demos.telerik.com/kendo-vue-ui/editor/schema-custom/source.txt)

## Suggested Links

* [API Reference of the Editor](https://www.telerik.com/kendo-vue-ui-develop/components/editor/api/editor)
* [ProseMirror Document Schema](http://prosemirror.net/docs/ref/#model.Document_Schema)