wrote

Yet at the same time, there are usually power classes
so the QRP' er isn't up against the big gun.

Makes sense to me. I don't think a 5W station out to be required with a 1500W
station. But within those power classes each operator ought to be able be a
creative as he desires in how he configures his station.

In some contests, packet spotting puts you
in a different class.

Packet spotting is a form of outside assistance, in effect a "Multi-Op" effort.
An SO entrant ought not be required to compete with Multi-Ops.

What about multiple simultaneous transmissions - say, calling
CQ on more than one band at a time?

No contest (that I know about) allows that in SO category. "Single transmitted
signal" is what defines SO.

Suppose someone builds a true robot station - automated
sending and receiving.

It would be a novelty, but not competitive. There is in fact a standing
"challenge" (side bet) for anyone who can field a robo-contester in one of the
popular events, maybe ARRL DX. Forget the details, but it must be able to
"participate" in the contest for some minimum time (6 hours?), and submit it's
own log untouched by human hands.

Or maybe not a total robot station, but rather a "new one
finder". Computer-controlled receiver scans up and down
each band, looking for callsigns that are not in the log already.
Alerts the op to a new one automatically. There could be
several of them, scanning each band simultaneously. (Useless
early in the contest, but as time goes on they could be very
helpful).

That's a logical extension of SO2R, and I believe that the station designer who
makes it work ought to remain in SO category and not be "punished" for his
innovation and design effort.

How about putting the entire FCC callsign database
in the computer in such a way that the op is given
"pointers"? These "pointers" could be things like
"callsign not in database", section/state/country, etc.
Could give best-guesses from partial callsigns too.

Would those things be OK in SO?

Similar things already exist. CT and NA both have a feature called "Super Check
Partial" which provide "matches" from a database of calls harvested from
previous contests. For example, if you enter the partial call "K0H", it will
show you several choices of calls like K0HA, K0HB, SK0HL, IK0HBN, all of which
contain the sequence "K0H". Because that's information not gathered "off the air
during the contest", purists consider it "outside assistance" and feel it should
disqualify the entrant from SO and place them in an assisted category.

Purists draw only this line between SO and "multi-op" or "assisted". Every bit
of information which goes into an SO log must be gathered off the air during the
contest period by a single operator and his equipment without outside assitance
such as packet clusters, harvested data-bases, and similar aids.

73, de Hans, K0HB