With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: In the ATA standard, pin 20 is defined as a mechanical key and is not used. An obstruction is often added to the socket for this pin on the female connector, which means that the male connector cannot include pin 20; this ensures that the plug cannot be inserted the wrong way around.
text_B: Does it sound like other standards that use this kind of 20-pin connector often necessitate that the plug be inserted one way, but not the other?
YES.