Tamely ramified covers of varieties and arithmetic schemes.

Let Y → X be an étale cover of regular varieties or arithmetic schemes. We give the following intrinsic characterisation of tameness: Y → X is tamely ramified (outside X), iff for every irreducible curve with normalisation the induced cover Y × X → is tamely ramified (outside ). 2000 Mathematics Subject Classification: 14G40, 14E20. [ABSTRACT FROM AUTHOR]