Important: The XMLOK command and ValidateXml functions just check that the XML file is well-formed according to the corresponding SAT specification. They do not verify the signature. There may be some attribute facets not detected that a more sophisticated XSD parser may find, and the SAT validator sites may do extra checks not strictly in accordance with the XML standards.

If XMLOK/ValidateXml finds an error, then your input XML file definitely has a problem that needs fixing. But we do not guarantee that an XML file shown as "OK" will pass all the tests on a SAT validator site.

See also XML restriction violated: Element must be empty

and Checks against XSD catalogs.