This article is from the soc.history.medieval FAQ, by Stephan Schulz email@example.com with numerous contributions by others.
The concept of the Crakow (occasionally "Krakow" or "Cracow" --
we are an international group with a flexible approach to
orthography) Vote came up in the second half of 1999 in a thread
on medieval Russia. The Crakow Vote is basically an appeal to
authority ("Argumentum ad verecundiam"), only without the
authority. The classical examples seem to be
"According to a poll taken among Krakow's cab drivers, Europe
ends on Poland's Eastern border".
"According to Cracow Vote, The Battle Which Can Not Be Named had
been won by the Fried Templars and/or McWasherwomen".
Crakow Votes can be used both seriously (but risking that people
will stop taking the speaker serious) or humorously (which,
unfortunately, does not automatically confer any special weight to
the speakers opinion).
New research has indicated that the preferred spelling is indeed
"Crakow". It is found in the oldest surviving documents, and has
the added benefit of being equally wrong in all known languages.