 A dummy board provides a minimal interface.This type of diagnostic board in intended to confirm that the interface is correctly implemented.For example, a PC motherboard manufacturer can test PCI functionality of a PC motherboard by connecting a dummy PCI board into each PCI slot on the motherboard

An extender board (or "board extender, card extender, extender card") is a simple circuit board that interposes between a card cage backplane and the circuit board of interest to physically 'extend' the circuit board of interest out from the card cage allowing access to both sides of the circuit board to connect diagnostic equipment such as an oscilloscope or systems analyzer.