RSMF: chat data as a production format
Relativity Short Message Format · what travels in the file, and what the DAT still has to carry
Chat is now a first-class data source — Slack, Teams, SMS/iMessage, Bloomberg — and reviewing it from a spreadsheet export is miserable. The Relativity Short Message Format (RSMF) is the closest thing the industry has to a standard container for it: an RFC 5322-compliant file (an email, structurally) that encapsulates a normalized conversation. Relativity reports over 75 chat applications converted to RSMF in its ecosystem.
Structure: header, body, attachment
| Part | Content |
|---|
| Header | X-RSMF-* fields. X-RSMF-Version is the only required one; optional fields include Generator (who made the file), BeginDate/EndDate (ISO 8601 span of events) and EventCount |
| Body | The extracted text of the conversation — this is what gets indexed and searched |
| Attachment | A zip (rsmf.zip) containing rsmf_manifest.json plus the attachments and avatar images |
The manifest is where the per-message fidelity lives — per-message timestamps, senders, reactions and events. It is not processed or searchable outside the viewer; the searchable layer is the body text. Emoji, reactions and inline images are supported through the manifest and attachments, which is why a chat "document" renders in the Short Message Viewer the way it looked on the phone.
Practical notes for productions
- It opens outside Relativity. Rename .rsmf → .eml and any email client shows headers, body and the zip. Useful for spot-checking a production without the platform.
- Attachments need their relationships. The recommended ingestion keeps attachment relationships intact (processing, or import + overlay) so files display in-line; a bare load that drops the relationship strands the attachments.
- The DAT row still governs. Each conversation is a document: the DAT carries its Bates range, custodian, date fields and family ranges exactly as for email. RSMF is the content container, not a replacement for the metadata load file.
- Production rendering. When a matter requires TIFF/PDF page images, the conversation gets rendered to pages like any other document — the RSMF remains the native-format artifact.
- Version. RSMF 2.0 added fields over 1.0; both are supported. Check the version header when reconciling exports from different tools.
Why it matters at the load file level
If your matter has chat data, your load file plan should say how it's produced: RSMF for the reviewable native, DAT/OPT for the metadata and page images, and a decision — recorded in the protocol — on whether per-message manifest data is produced at all. A production that delivers only spreadsheet text of chats loses timestamps and reactions; a production that delivers only RSMF without the metadata row gives the receiving party nothing to search or Bates.
Basis & sources
Primary sources only — the statute, form or paper this page is built on.
Last reviewed 2026-10-26 · Report a correction
FAQ
What is an RSMF file?
A Relativity Short Message Format file: a standards-compliant RFC 5322 (email) file that encapsulates normalized chat data. The body carries the conversation text, and an attached rsmf.zip contains rsmf_manifest.json plus the attachments and avatars.
Where is per-message metadata stored in RSMF?
In rsmf_manifest.json inside the zip: per-message timestamps, senders and events. That data is not processed or searchable outside the Short Message Viewer — the email body only carries the extracted text.
How do I open an RSMF file without Relativity?
Rename the extension to .eml and open it in any email application: you'll see the X-RSMF headers, the conversation text as the body, and the rsmf.zip attachment.