From Sky News:

Taxis with "unlucky" number plates in Shanghai are to stop operating during university entrance exams to appease superstitious parents.

"All cabs with number plates ending with the number 'four', which shares the same pronunciation as 'failure' in the Shanghai dialect, will not be used," Shanghai's biggest taxi company Shanghai Dazhong tells the China Daily's website.

I can't help but notice that the Anglo-Saxon Archaeology paper I sat - the one whose instructions I overlooked in an act of sublime stupidity - was paper number 3031. There's a backwards 13 in there! No wonder I messed it up.