common-lisp:simple-error, common-lisp:simple-condition, common-lisp:error, common-lisp:serious-condition, common-lisp:condition, sb-pcl::slot-object, common-lisp:t

The class of all validation and schema parsing errors.

Signalled while parsing a schema, this error signifies that the schema is incorrect (or not compatible with DTD Compatibility). Signalled during validation, this error signifies that the document is invalid (or not sound).

When parsing or validating with DTD Compatibility, check for dtd-compatibility-error to distinguish between correctness and compatibility or validity and soundness.