This code system http://ehealth.sundhed.dk/cs/derived-quality-base defines the following codes:
| Code | Display | Definition |
| Unknown | Unknown | Unknown quality (Unlikely to be adequate where one is expected) |
| None | None | Quality value where no derivation rule logic and/or values are expected |
| DerivationError | Error in deriving the quality | Quality value could not be derived due to insufficient input, unknown/unavailable logic, or other error. |