ring value that does not contain spaces.</p>
</td></tr><tr><td style="white-space: nowrap">Short</td><td>Unique id for inter-element referencing</td></tr><tr><td style="white-space: nowrap"><a href="http://hl7.org/fhir/R4/conformance-rules.html#conformance">Control</a></td><td>0..1</td></tr><tr><td style="white-space: nowrap"><a href="http://hl7.org/fhir/R4/datatypes.html">Type</a></td><td><a href="http://hl7.org/fhir/R4/datatypes.html#string">string</a></td></tr><tr><td style="white-space: nowrap"><a href=