G'day Norm,
It is in fact relatively easy to remove and drain a motorcycle fuel tank, as you know. And indeed, this should always be done, followed by airing out to evaporate the residual fuel.
On the Consignment Note, there is always a question asking whether the shipment contains any Dangerous Goods, requiring the consignor's signature - it's part of the 'boilerplate' T&C of acceptance for carriage, for every commercial carrier I've ever used. False declarations here are subject to severe penalties, too...
One example I've come across recently, is that railways will no longer accept any petrol fuelled motorcycle or moped for carriage, if it has been run at all, or even uncrated and assembled.
They were once rather easygoing about putting your bike in the guards van of country passenger trains, as 'accompanied luggage' - I've done that several times in Vic, back in the day when a 250cc bike was my sole transport.
And airlines have long been very strict on this, as you might expect. One lurk I recall with airfreighting bikes, was to remove the fuel tank and pack it separately. That way only the fuel tank was charged at DG freight rates, rather than the entire bike!
Then too, airlines will no longer accept any small engine powered OPE equipment, unless it is 'factory new in box'. Too many instances of people shipping them with fuel in the tanks...