Followup to 16480 which was deemed non-persuasive.

From narrative.html - markup is recommendation to differentiate guidance from normative. With more specific use of UPPERCASE normative words, vs different non-normative words (can, will, would).

Any resource that is a DomainResource (almost all types of resource) may include a human-readable narrative that contains a summary of the resource, and may be used to represent the content of the resource to a human.

If narrative is present with a status other than 'empty', it SHALL reflect all content needed for a human to understand the essential clinical and business information for the resource. * In other words, - *it must * It SHALL + *be safe to render only the narrative of the resource without displaying any of the resource's discrete/encoded information. Resource definitions and/or profiles on resources * -may * * +MAY * define what content should be represented in the narrative to ensure clinical safety.

The narrative for a resource * can * * MAY * contain additional information that is not in the structured data, including human-edited content. Such additional information SHALL be in the scope of the definition of the resource, though it is common for the narrative to include additional descriptive information extracted from other referenced resources when describing references. Narrative for a resource * should * * SHOULD * include summary information about any referenced resources that would be required for a consumer of the resource to be able to understand the key, essential information about a resource without retrieving any additional resources.

For example, the narrative for a MedicationRequest might include brief summary information about the referenced patient, prescriber and medication. Some resources (e.g. List, Composition) * may * * can * provide specific rules about what content must (or must not) be included in the resource narrative. Consideration * should * * would * be given to the fact that referenced resources may be updated without updating referencing resources, so the proportion of content of a referenced resource included in a referencing resource should be limited.* _ CR/LF to break the informative example from following normative_ *

Systems MAY choose how narrative is generated, including how much de-referencing to perform, but SHALL NOT assume that the resource is rendered in any particular context when generating narrative, since resources will be used in multiple contexts.

Resources SHOULD always contain narrative to support human-consumption as a fallback. Structured data SHOULD NOT generally contain information of importance to human readers that is omitted from the narrative. Creators of FHIR resources should not assume that systems will render (or that humans will see) data that is not in the narrative. However, in strictly managed trading systems where all systems share a common data model and additional text is unnecessary or even a clinical safety risk, the narrative may be omitted. Implementers should give careful consideration before doing this, as it will mean that such resources can only be understood in the limited trading environment. Closed trading partner environments are very likely to open up during the lifetime of the resources they define. Also, many workflow steps involving finding and aggregating resources are much more difficult or tedious if the resources involved do not have their own text.

• In some cases, a * * A * resource * may * * MAY * only have text with little or no additional discrete data (as long as all minOccurs=1 elements are satisfied). This * may * * can * be necessary for data from legacy systems where information is captured as a "text blob" or where text is additionally entered raw or narrated and encoded in formation is added later.

Note that contained Resources SHALL NOT have a narrative of their own.

The narrative - is - * SHALL BE * an XHTML fragment with a flag to indicate its relationship to the data: