Virtually all errors raised by the RTML 2.3 wrapper object come from the underlying XML engine. When RTML.AttachXML() is called, the supplied RTML is validated against the RTML 2.3 Schema. If the document is invalid, an error is raised. There are many of these possible. Conversely, when RTML.XML() is called, the generated RTML is checked against the RTML 2.3 Schema, and if the object tree is missing required elements or if some element is syntactically incorrect, an error is raised.
The only other errors that can be raised are (a) if the RTML.version attribute doesn't have values 2.1, 2.2, or 2.3, and (b) attempts to use elements and attributes belonging to a higher version of RTML than the current value of the RTML.version attribute.