It cannot be applied if the type attribute is set to , the presence of this Boolean attribute indicates that the control is selected by default; otherwise it is ignored.
Firefox will, unlike other browsers, by default, persist the dynamic checked state of an event will not be dispatched on disabled controls.
Also, a disabled control's value isn't submitted with the form.
Firefox will, unlike other browsers, by default, persist the dynamic disabled state of an If the input element is a submit button or image, this attribute is a name or keyword indicating where to display the response that is received after submitting the form.
This is a name of, or keyword for, a events as the user edits the text value.