There is a Role Type that allows to group roles by their type. There may be administrator roles and user roles. The type Administrator and the type User will not be shared with any other document types.

In contrast the Tag named Security may be used by all doctypes like Role, Topic, and Tour.

Do not be confused that there is a Tag Type to group tags. You can also tag documents of doctype Tag with the Tags property. The Type property of a tag document will point to a document of type Tag Type.