[AT] Electrical question

[JParks]

Disconnect field!?

I just got a "new' machine today.....and on a decal attached
to the battery box it said "disconnect field before removing, charging, or
jumping battery"

I got into the operator's manual to see why/what was going on and sure
enough they give pretty explicit warnings to disconnect the alternator diode
connection (field connection)

I have never run across this before..!? (to my meager recollection) but
would like some insight as to this particular setup and why it would require
this type of warning.   Is this just an overzealous warning label or is
their a real purpose?

Thanks
John Parks
Boise, ID