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A valid XML document contains a proper document type declaration and obeys the constraints of that declaration (correct elements, nesting, attributes, attribute values, and so on). As a test suite tool, it allows you to check XML as part of your functional test scenario. To check XML during static analysis, use the "Check XML Well-formedness" rule, which is in the Validate XML category. This rule has the same customization options as the XML Validator tool. 

Customizing XML Validator

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