A Parser may attempt to insert multiple instances of an element in the output XML. The Script uses the schema to determine whether to append new instances or overwrite existing elements. The Parser deletes any excess elements beyond those that the schema permits, and it writes warnings in the event log.
In another example, suppose the schema defines an element without specifying a
attribute. The default
values are 1, which means that the element must occur exactly once in the Parser output. If the element is missing from the output, the Parser can add it.