An Unstructured Document (UD) document type can (1) include unstructured content, such as a graphic, directly in a text element with a mediaType attribute, or (2) reference a single document file, such as a word-processing document using a text/reference element. For guidance on how to handle multiple files, on the selection of media types for this IG, and on the identification of external files, see the examples that follow the constraints below. IHE’s XDS-SD (Cross-Transaction Specifications and Content Specifications, Scanned Documents Module) profile addresses a similar, more restricted use case, specifically for scanned documents or documents electronically created from existing text sources, and limits content to PDF-A or text. This Unstructured Documents template is applicable not only for scanned documents in non-PDF formats, but also for clinical documents produced through word processing applications, etc. For conformance with both specifications, implementers need to ensure that their documents at a minimum conform with the SHALL constraints from either specification.