...
| Fields | Description | Required | Repeatable | ||
|---|---|---|---|---|---|
| Instrument | Holds information about the instrument (usually a questionnaire) | Yes | Yes | ||
| Agency | The DDI agency identifier for the metadata e.g. uk.alspac, uk.cls.mcs | Yes | No | ||
| InstrumentName | Title of the instrument | Yes | No | ||
| Version | Yes | No | |||
ControlConstruct | Yes | No | |||
| Sequence | Yes | Yes | |||
| QuestionConstruct | Yes | No | |||
| IfThenElse | No | No | |||
| Loop | No | No | |||
| StatementItem | No | No | |||
| Version | Yes | No |