FHIR elements can reference other resources by their canonical URL. A canonical reference refers to the standard URL associated with a FHIR item. For elements that require a canonical datatype, FSH accepts a URL or an expression in the form Canonical({name or id or url}). Canonical() stands for the canonical URL of the referenced item. For items defined in the same FSH project, the canonical URL is constructed using the FSH project's canonical URL. Canonical() therefore enables a user to change the FSH project's canonical URL in a single place with no changes to FSH definitions.

Split text for instance and profile and add examples for local and remote canonicals. E.g.