Created attachment 110600 [details]
Screenshot of a circular Help button to show the desired appearance
VCL should parse any action button with the stock content “gtk-help” and make it render the circular Help button that is used in native OS X applications.
This page  says: “To define a Help button in your code, use the setBezelStyle: method of NSButtonCell with NSHelpButtonBezelStyle as the argument.” If this is of any help.
Migrating Whiteboard tags to Keywords: (needsDevEval, topicUI)