[re port pin RA4]
|     Yep, that's why its open drain.  Must limit to +14V and if driving a
|     relay, watch out for back EMF.

Is the +14 limit documented anyplace?  All of the PIC books I've seen
document the max on "any pin other than /Mclr" as Vdd.  Does Microchip
"officially" allow RA4 higher?