For production deployments, it is best to delete the default Document class if you do not use it. See How Classes Impact Performance.

You can define multiple classes in the Data Model. You can also alter this by custom analysis code.

Classes can be independent, or hierarchized. In a hierarchy, a class inherits all of its parent’s properties.

For example:

This means you can search for B_gizmo, B_foo, B_bar, A_foo, or A_bar.

You can specify which class in the Data Model is the default class. When searching for properties from this class, you do not need to prefix the search by the class name. For example, if B was the default class, searching for gizmo returns the same result as searching for B_gizmo.

Adding multiple classes presents some limitations and has an impact on resource consumption. See How Classes Impact Performance.