HL7 RDF Table Row Definition

Query and response fields from experience.
HL7 field reference RDF fields from HL7 v2.5.1 Show fields

These are the generated fields for the version selected at the top of the page. The document stays the same, but the reference panel follows that version.

Fields

FieldNameRequiredRepeatableTypeTable
RDF.1 Number of Columns per Row Yes No NM
RDF.2 Column Description Yes Yes RCD 0440

RDF defines the columns in a tabular query response.

The standard describes RDF this way: The RDF segment defines the content of the row data segments (RDT) in the tabular response (RTB). • As an optional segment in a query either a QBP or QBS, this segment can be used to limit the number of columns returned and to specify what column positions the fields occupy (where supported, these features can be used to override the defaults for the particular query). If omitted, all fields defined for the query are returned in their default column order. • As a required segment in a tabular response (RTB) to either a QBP or QBS, this segment defines the contents of the table row data (RDT) segments that follows. It is not necessarily an echo back of the segment as it appeared in the query.

Query segments define what the sender is asking for, how the receiver should format the answer, and how a multi-message response is continued or limited.

A query is an interface contract. The tag, parameters, row definitions, sort/filter rules, and continuation pointers must match exactly or the receiver may return technically valid data that is not what the requester expected.

The v2.5.1 structures show RDF in QBP_Q13 - QBP - Query by parameter requesting an RTB - tabular response, QBP_Qnn - Query by parameter, RSP_K11 - RSP - Segment pattern response in response to QBP^Q11, and RTB_K13 - RTB - Tabular response in response to QBP^Q13, and 4 other message structures. That tells you where it can appear, but the implementation guide still decides which optional fields are meaningful.

For practical interface work, read the generated field panel for datatype, required, repeatable, and table details, then use the notes below to decide what the field should mean in the receiving workflow.

RDF-1 Number of Columns per Row RequiredR SingleS TypeNM

RDF-1 is a count or total for this query workflow. Make the counting rule explicit before using it for reconciliation, billing, or workflow limits.

RDF-2 Column Description RequiredR RepeatableR TypeRCD Table0440

RDF-2 is human-readable context. Keep it useful for display and troubleshooting, but do not hide required workflow logic here unless the implementation guide explicitly says the receiver parses it.

Because the field can repeat, separate distinct statements into separate repetitions instead of creating one long hard-to-parse block.

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