I read here that \"self Refers to the current window or form\".
Self does not seem to refer to the current form in this case:
For all windows, the
selfandwindowproperties of awindowobject are synonyms for the current window, and you can optionally use them to refer to the current window. For example, you can close the current window by calling theclosemethod of eitherwindoworself. You can use these properties to make your code more readable or to disambiguate the property referenceself.statusfrom a form calledstatus.