In pattern The Open Schematron DTD: A schema element should contain at least one pattern elements. In pattern The Open Schematron DTD: A pattern element should contain at least one rule elements. In pattern The Open Schematron DTD: A pattern element should have an attribute called name. In pattern The Open Schematron DTD: A rule elemement should contain at least one assert or report elements. In pattern The Open Schematron DTD: A rule element should have an attribute called context. This should be an XPath for selecting nodes to make assertions and reports about. In pattern The Open Schematron DTD: An assert element should have an attribute called test. This should be an XSLT expression. In pattern The Open Schematron DTD: A report element should have an attribute called test. This should be an XSLT expression.