It may not be the most pressing issue in the referendum, but it must nevertheless must be considered:

what should happen to the Union flag if Scotland votes for independence?

Scotland for its part already has a flag doing sterling service in the shape of the Saltire. The flags of Australia and New Zealand incorporate the Union flag in one corner, reflecting those countries' historic ties to the UK, but there would probably be little appetite for doing that to the Saltire.

What about the Union flag? Any redesign would be an overdue opportunity to represent Wales, which perhaps wins the prize for best flag in the British isles with its striking red dragon passant, but change is perhaps unlikely. Some have suggested that, with the Queen remaining Scotland's head of state, no change would be necessary. Altering it would also be a huge undertaking, given how well recognised it is worldwide. The multimillion-pound renaming of former utility companies would pale into insignificance by comparison with trying to rebrand the UK.

Should it ever happen, though, the debate on what should replace it might prove as contentious as the referendum that prompted it.