_NameSpace.Categories Property

Returns or sets a Categories object that represents the set of Category objects available to the namespace. Read/write.

Namespace:  Microsoft.Office.Interop.Outlook
Assembly:  Microsoft.Office.Interop.Outlook (in Microsoft.Office.Interop.Outlook.dll)

Categories Categories { get; }

This property represents the Master Category List, which is the set of Category objects that can be applied to Outlook items contained by the NameSpace object, and applies to all users of that namespace.