What are categories?

A category is a type of field you can assign to a custom property in an AODocs document.

A category is composed of a set of defined values. For example, a category could have a list of electronic products. Users can select predefined values for a category in a drop-down list in the edit mode of a document.
Library administrators can create and configure categories.

Category values can have several hierarchical sublevels. For example, the category Country may have three sublevels: Region, Country and Territory/Town.

A list of category values can be dynamic. This means that contributors can add new values to the predefined list. Alternatively, the list can be frozen and contributors can only select values from the predefined list.

Categories are configured at the library level and can be assigned as a field type for several custom properties from the same document class or from different document classes.
The property with a category field type can be mandatory, hidden or have multiple values.