Shared display generally relates to a CRT based Operator Station where there may be many Operator stations in one location or in various locations. A Flow Controller for example may be called up on any of these locations ie: Shared Display.
Board I assume for example, you would mean a conventional Flow Controller mounted on a conventional control panel.
ISA show the PID symbol for shared display with a Square around a Circle. If the operator access is located at the control room then there should be a single line through the center of the circle. If the operator access is local in the field there is no line.
ISA show the PID symbol for conventional instruments Circle only. A conventional control panel device will be shown with a line through the middle of the circle. Field devices will be shown with the circle only.
See ISA standard ISA-S5.1