VISIT — select records for inclusion by the visit identifier
Records are selected by visit identifier with this element.
If the visit identifier of a record is in the range of included visit
identifiers
(specified by the value of the include
attribute), the record becomes part of the set of records to be processed.
If no inclusion criteria are specified,
records are selected for inclusion independent of the visit identifier.
This is equivalent to not specifying a VISIT
element.