By default, the Help keyword for a class is given by the Type.FullName property value. For members, the Help keyword is given by the full name of the type that declared the property, plus the property name itself.

For example, consider the System.Windows.Forms.Control.Text property on the System.Windows.Forms.Button control. The class keyword is "System.Windows.Forms.Button", but the System.Windows.Forms.Control.Text property keyword is "System.Windows.Forms.Control.Text", because the System.Windows.Forms.Control.Text property is declared on the System.Windows.Forms.Control class, rather than the System.Windows.Forms.Button class itself; the System.Windows.Forms.Button class inherits the property.

By contrast, the System.Windows.Forms.Button.DialogResult property is declared on the System.Windows.Forms.Button class, so its keyword is "System.Windows.Forms.Button.DialogResult".

When the Help system gets the keywords, it will first look at System.ComponentModel.Design.HelpKeywordAttribute. At the class level, it will return the string specified by the System.ComponentModel.Design.HelpKeywordAttribute. This will not be used for members of the type in question, which will still reflect the declaring type's actual full name, plus the member name. This attribute supports strongly typed classes that have associated common documentation but distinct Help IDs.