TActionLink descendants call IsHintLinked to determine whether they need to propagate changes to the Hint property of the action so that they are reflected by the client object. When IsHintLinked returns true, the action controls the Hint property: Changes to the Hint property of the action are reflected by changes to the corresponding property of the client object. When IsHintLinked returns false, the client object does not reflect the Hint property of its action, either because it does not have a corresponding property, or, more commonly, because it manages the value of its corresponding property independently. 

As implemented in TActionLink, IsHintLinked merely checks that the Action property specifies a descendant of TCustomAction (that is, it is an action that has a Hint property). Descendant classes override IsHintLinked to determine whether the Hint property is linked with the appropriate client property. 

Hint 

Hint 

Hint 

SetHint 

Action