The method
wfcElement::GetDiagnostics collects the element diagnostics. The diagnostics include warnings and errors about the value of the element within the context of the feature and the remainder of the element tree.
Use the method
wfcElementDiagnostic::Create to create an element diagnostic in an element tree.
The methods
wfcElementDiagnostic::GetDiagnosticMessage and
wfcElementDiagnostic::GetSeverity get the message and severity of the diagnostic item of the element.