#### Interoperability Toolkit
Clinical Correspondence Metadata

### Metadata Overview

The metadata is based on a subset of IHE's Extrinsic Object metadata profile, which in turn is based on based on OASIS ebXML Registry standard. If a more extensive metadata set is required, for example to support a Cross Enterprise Document Sharing (XDS) repository, then the relevant IHE specification should be consulted. The metadata standard defined here may be extended in line with the IHE metadata standard.

Within the ITK Distribution Envelope, only one metadata payload is allowed. The ITK metadata standard uses the itkmetata.xsd schema as a wrapper to hold multiple ExtrinsicObjects. Each clinical document payload has only one ExtrinsicObject, but the metadata payload is capable of holding metadata for multiple clinical documents.

The metadata payload is identified by the manifestItem metadata attribute being set to true in the Distribution Envelope of the wrapped message. The metadata payload will always begin with the tag.

The example below shows a DistributionEnvelope that contains a CDA document that has associated metadata.

An example of multiple ExtrinsicObjects in a metadata payload