Danish has an official 32 page booklet on the comma rules. I have not read it. Though to be honest, from Wikipedia it sounds like they have shifted them around a bit and Danes have agreed that they honestly prefer them as decorative sprinkles. Ah! This is a surprisingly comprehensible Danish account of the whole business, though I am now worrying that I haven't a clue how I should use commas in German.

I'm almost tempted to nominate Danish comma rules for next year's Yuletide.