Description
Distinguish the raw HL7 two-quote null indicator, empty text and other values.
Health-information systems separate identifiers, code-system namespaces, source versions, missing-value states and reference syntax. Recording a mapping or recognizing a restricted token does not validate its clinical meaning or a complete HL7/FHIR resource. Explicit null, empty text, unknown status and numeric zero are different states.
Distinguish the raw HL7 two-quote null indicator, empty text and other values.
When to use this tool
Use HL7 Null Empty Value Distinction when checking the stated restricted health-data record, token or transition convention.
How to use the tool and how it works
- Enter rawFieldToken. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read presenceCode. Use the output convention below.
Return explicit-null only for the raw field token consisting of two double quotes. Return empty for a zero-length token; every other string returns value.1
HL7 distinguishes the two-quote delete indicator from an empty field. This helper classifies raw tokens; receiver actions still depend on the message profile.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| rawFieldToken | Raw string: exactly two double-quote characters means explicit-null, empty text means empty, all other text means value. | Required. Text; maximum UTF-16 length 8192. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| presenceCode | Presence Code | Required. Text; maximum UTF-16 length 8192. |
{
"input": {
"rawFieldToken": "\"\""
},
"output": {
"presenceCode": "explicit-null"
}
}Limitations and assumptions
- This recognizes one raw HL7-style presence convention; it does not parse escapes, interpret a datatype or validate a message.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
Alternative or Complementary methods
Use the intended complete interoperability specification, authoritative terminology and verified source records for actual resource validation, semantic mapping or clinical use.
References
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