The internal pullups are "invisible" in the sense that their circuitry is inside the Arduino "black-box" in a schematic. The code would show that a pin had its pullup enabled, but one doesn't know that from the schamatic: one would simply see (eg) a switch across the pin and ground.
Is there a) any need to and if so b) any way to show an "invisible" internal pullup on a schamatic?
(I was thinking of showing it as an external resistor, but with a dotted line?... kind of "greyed ot" so to speak.)