Agree, using guard for company messages is unprofessional, with the possible exception of a brief call to establish contact and tell the other guy to "go company".
But what REALLY gives me the sh*ts is these bloody "practice pan" calls in the UK. I'm know they're useful to all concerned - both student and D&D - but they'll be just as useful if made on a dedicated "practice pan" frequency. They don't bloody well belong on 121.5. Any suggestions as to how we can get the Belgrano to take some action on this - or do we have to wait for the inevtiable cock-up and possibly some lost lives before they do........??
Rant over!