HL7 v2 continuation (DSC and MSH-14)

HL7 v2 continuation splits a response too large for one message across several. The sending system ends a partial message with a DSC segment whose DSC-1 continuation pointer names where the interrupted result set resumes; the receiver requests the next chunk quoting that pointer, and follow-on messages carry it in MSH-14. The protocol is most common on query responses and large document messages.

DSC-1	Continuation pointer: ST, optional, max length 180 (v2.3)
MSH-14	Continuation pointer on the follow-on message, matching the DSC-1 that ended the previous one
End of data	The final message carries no DSC segment
Where seen	Query responses (QRY/DSR era), large document and result sets

Example

Message 1 (partial result set)
  MSH|^~\&|LAB|FAC|EHR|FAC|20260722||DSR^Q03|0001|P|2.3
  ...first 50 result segments...
  DSC|CONT-8842

Message 2 (resumes where message 1 stopped)
  MSH|^~\&|LAB|FAC|EHR|FAC|20260722||DSR^Q03|0002|P|2.3|||||||||CONT-8842
  ...remaining result segments...
  (no DSC segment: the result set is complete)

Hand-authored illustration of the two-message flow; segment layout follows the standard, values are invented. The pointer value is opaque: only the system that issued it needs to understand it. DSC-1 facts verified with pidgeon lookup.

Validation context

Strict and compatibility validation notes land here with the phase-1 data export.

This answer, in your terminal

pidgeon lookup DSC.1

Wire it into your AI agent:

claude mcp add pidgeon -- npx -y @pidgeonhealth/mcp

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