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 !!!!!s 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!