Football hooligans are finding an unexpected letter in their post boxes as the Euro 2008 championship opens, the Blick newspaper reported on Thursday.
It comes from the police and is polite but firm: "We know you as a person who hasn't always followed the rules at sports events." It warns that no rowdy behaviour will be tolerated during the championship.
An outline letter was drawn up by the federal police last month, and sent out to all the cantonal police forces to forward.
The central hooligan database contains 300 names, and the cantons have their own additional lists, so it is not known exactly how many people are being targeted.
The police say the letter is only a warning, and that known hooligans will not have their movements restricted in any way as long as they behave.
The first match, between Switzerland and the Czech Republic, kicks off on Saturday.
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