Excuse my ignorance, but what is the "Butcher's Apron"?
Its the union flag.
All flags have their place and when I'm on duty at Solway Aviation Museum I run up the butcher's apron on the flagpole, which is in my view the appropriate flag for a museum of Royal Air Force artefacts coveing an area having both English and Scottish coastlines. I'm always careful to hang it correct side up.