In the days of coaching to the "November" stands at LHR T1, Teesside and Leeds passengers sometimes got boarded on the wrong aircraft.
Very often, it was prudent to yell up the steps to the cabin crew "Is this for Teesside?" in the style of passengers at a 1960s bus station.
And then there were the cases of passengers having to step over the tug's bar which had been left at the bottom of the front stairs....