Element. A keynote can be applied to an entire element, such as a wall, detail component, or door.
Material. A keynote can be assigned to a material that has been painted on a surface, and to materials assigned to the component layers of an element. Material keynotes are not supported for the insulation drafting tool, the detail components line and filled region, or wireframe views.
User. This option provides a way to use commonly used notes or phrases to address documentation issues. These additional user notes must be added to the provided keynote text files or included in one that you create. See Adding Keynote Categories.