Orig. 128k Logic Board Location C1?

Anybody know what the original purpose of the empty C1 location on the fist Mac 128k logic board? There is also an empty spot for a resistor marked R11 next to it. There appear to be no traces connecting to either of them, so it seems to be a vestige left over from an earlier design. Both were completely removed on the 128k/512k hybrid board and (not that they have anything to do with each other) CR1 returned again unfilled on the Plus logic board along with an actually resistor in R11. In looking over the various prototypes of the original logic board at Digibarn, the C1 location is filled on almost all of them by what looks like a red LED. That really got my curiosity up!Was it possibly used for testing?