http://terminology.hl7.org/CodeSystem/v3-NullFlavor| Code | Display | Definition |
| ASKU | asked but unknown | Information was sought but not found (e.g., patient was asked but didn't know) |
| MSK | masked | There is information on this item available but it has not been provided by the sender due to security, privacy or other reasons. There may be an alternate mechanism for gaining access to this information. Note: using this null flavor does provide information that may be a breach of confidentiality, even though no detail data is provided. Its primary purpose is for those circumstances where it is necessary to inform the receiver that the information does exist without providing any detail. |
| NA | not applicable | Known to have no proper value (e.g., last menstrual period for a male). |
| NASK | not asked | This information has not been sought (e.g., patient was not asked) |
| NAV | temporarily unavailable | Information is not available at this time but it is expected that it will be available later. |
| NI | NoInformation | **Description:**The value is exceptional (missing, omitted, incomplete, improper). No information as to the reason for being an exceptional value is provided. This is the most general exceptional value. It is also the default exceptional value. |
| UNK | unknown | **Description:**A proper value is applicable, but not known. **Usage Notes**: This means the actual value is not known. If the only thing that is unknown is how to properly express the value in the necessary constraints (value set, datatype, etc.), then the OTH or UNC flavor should be used. No properties should be included for a datatype with this property unless: 1. Those properties themselves directly translate to a semantic of "unknown". (E.g. a local code sent as a translation that conveys 'unknown') 2. Those properties further qualify the nature of what is unknown. (E.g. specifying a use code of "H" and a URL prefix of "tel:" to convey that it is the home phone number that is unknown.) |