There is not much that can be done regarding strict constraints within the scope of an interoperability FHIR implementation guide. However, we will add the following guidance to the guide that will make the situation clear and note considerations for code display values, text rendering as defined in the resolution in   FHIR-31069 . Summarized for this ticket: Add guidance in general guidance section (under CapabilityStatement Server Requirement) called "Payer Considerations for App Rendering" Many of the codes used in this guide are proprietary with  [licensing requirements] (Terminology.html). While it is recommended that consumer apps acquire the necessary licenses to show descriptions for these codes, not all app developers may be in a position to do so. Because of this, payers  MAY  choose to provide a concept text ` [CodeableConcept] .text` or the coding display ` [CodeableConcept] .coding.display. It is the responsibility of the payer to make sure that the descriptions provided are correct.   If the 'display' element is populated, the string used in ` display `  SHALL  be one of the display strings defined for that code by the code system (code systems may define multiple display strings for a single code). With the additional statement noting that  "If the code description available is not known to be an exact match of a display string defined by the code system, the  ` [CodeableConcept] .text` should be used in place of the ` [CodeableConcept] .coding.display`."