Specifies a region within the medium that is available for rendering with four comma separated measurements representing the measurements for x, y, width, and height.Reference_Syntax.bind = “none | x, y, width, height“
• none (default)
• The content of the subform is not available for manipulation by the user. A user-agent should treat the subform as a pass-through container in sequencing operations, and you must not be permitted to modify the content of the subform. The content of the subform is still modifiable via indirect means such as scripting operations and calculations.