[Elecraft] FP ACC Function = ?

[n1wr at chesapeake.net]

K3 s/n 1945 is up and running, to the tune of 1200 plus QSOs in CQWW this
weekend.

Reading the manual I saw a reference to the front panel accessory
connector.  On page 16 in the manual. It's the RJ-45 connector on the
underside of the radio.  The manual says simply that it is used with
accessory devices, but no other information is given.

Being of the inquisitive sort I tried to find it on the schematics, but it
sure isn't obvious, if it is there.  Anyone know what the intended
function is?  Is it documented (pinout) anywhere?

Thanks,  Wayne N1WR