4fd402ae__Controls_in_Practice___Page_5__Description
[Attribute] Category [Operates On] Property, event [Description] 
Organizes your property into one of the existing categories (e.g. Accessibility, Appearance, Behavior, Data, Design, etc.) in the property grid or a new one of your own choosing. Only relevant when the property grid is set to Categorized mode (as opposed to alphabetic mode).
.NET Building Blocks: Custom User Controls in Practice : Page 5