| Code | Display | Definition |
| not-found | Not Found | An issue that identifies a code system or value set that was not found validating the code(s) |
| not-in-vs | Not in ValueSet | An issue that represents the value set validation failure |
| this-code-not-in-vs | This code not in valueset | An issue that indicates that a particular code as not in the value set (but others might be) |
| invalid-data | Invalid Data | An issue that indicates that the code/Coding/CodeableConcept provided was invalid |
| invalid-code | Invalid Code | An issue that indicates that a provided code is not valid in a code system |
| code-comment | Code Comment | An issue that provides some hints or warnings about the use of the code, but does not indicate that is invalid |
| invalid-display | Invalid Display | An issue relating to the display provided for a code |
| display-comment | Display Comment | An issue that provides some hints or warnings about the use of the display, but does not indicate that is invalid |
| cannot-infer | Cannot Infer System | An issue indicating why inferring the code system failed (for type=code) |
| code-rule | Code Rule | An issue indicating that a valid code was not valid in this context |
| vs-invalid | ValueSet Invalid | An issue relating to a problem processing a value set while validating |
| status-check | Status Check | An issue pertaining to the status of the underlying resources |
| cannot-determine | Cannot Determine | An issue indicating that the server was unable to determine the answer to the question it was asked, and is declining to give one rather than giving one that may be wrong. This arises where an operation's outcome codes have no value meaning "unknown": $subsumes, for instance, can answer equivalent, subsumes, subsumed-by or not-subsumed, so a server that cannot establish the relationship - between SNOMED CT expressions that no classifier has seen, or between media types differing in a parameter the server does not understand - has no outcome it can honestly return. The client should treat the relationship as undetermined; it must not read this as a negative answer |
| not-supported | Not Supported | An issue indicating that the server understood the request but does not implement what it asks for: a parameter, filter or property it does not support, or a code system whose codes it cannot enumerate at all. The request is not wrong, so repeating it against this server will not produce a different answer, but another server may be able to give one |
| too-costly | Too Costly | An issue indicating that the server can work out the answer but the answer is too large or too expensive to produce - typically an expansion with more members than the server is prepared to return. Nothing is wrong with the value set: the client should narrow the request with a filter, or page through it with count and offset |
| version-error | Version Error | An issue arising from the versions of the resources involved rather than from the code or the value set: a version was asked for that does not exist, the same code system was pinned to two different versions in the one request, or a value set's stated version does not match the version it was fetched by. The client can usually recover by changing or dropping the version it named |
| business-rule | Business Rule | An issue indicating that the server is declining to process content because of a rule it enforces about what it will accept, rather than because the content is invalid - a resource carrying implicit rules or modifier extensions it cannot safely ignore, say, or a compose with a lockedDate. The content may be perfectly valid; this server will not act on it |
| cache-id-duplicate | Duplicate Cache Id | An issue indicating that the request carried more than one cache-id. Each request must carry exactly one; a server has no way to choose between them. This is a client error, and usually means a second cache was started on a connection that already had one without the first cache-id being removed |
| cache-id-unknown | Unknown Cache | An issue indicating that the cache-id provided by the client is not known to the server: it was never created (caches are created with $cache-control mode=start), or it has expired or been released. The client cannot continue to refer to resources by that cache-id, and should establish a new cache if it wishes to keep using one |