Build Concordance/Relativity Load File (DAT + OPT)

Skill: Convert a processed document set into Concordance DAT + Opticon OPT load files

Region: United States Category: Legal / eDiscovery Does: Takes a processed ESI document set and assembles the Concordance DAT (delimited metadata) and Opticon OPT (image cross-reference) load files — the de-facto standard pair for importing documents, metadata, and images into Concordance, Relativity, and most review platforms. Spec: Concordance DAT (Concordance default delimiters) + Opticon OPT image load file (industry standard)

DAT/OPT is an industry convention, not a published government schema. The single most common failure is delimiter handling — Concordance's defaults are non-printable ASCII characters chosen so they never collide with document text. Always confirm the receiving party's load-file specification (field list, order, delimiters, date format, path style) before delivery; many ESI protocols dictate it exactly.

The two files

Concordance default delimiters

The first row of the DAT is the header (field names, same delimiters). Every value is wrapped in the text qualifier; multi-value fields (e.g. multiple recipients) separate entries with the newline character.

Typical DAT fields

BEGBATES, ENDBATES, BEGATTACH, ENDATTACH        (Bates + family boundaries)
CUSTODIAN, DUPCUSTODIAN
DOCTYPE, FILEEXT, FILENAME, FILESIZE
FROM, TO, CC, BCC, SUBJECT                        (email)
DATESENT, TIMESENT, DATERCVD, DATECREATED, DATEMOD
MD5HASH (or SHA1HASH)
NATIVEPATH, TEXTPATH, PAGECOUNT
CONFIDENTIALITY                                   (designation, if produced)

BEGATTACH/ENDATTACH define the family range (parent Bates → last child Bates).

Opticon (OPT) format

Comma-delimited, one row per page image:

ImageKey, VolumeLabel, FullPath\Image.tif, DocBreak(Y/blank), , , PageCount

• ImageKey is usually the page's Bates number; the first page of a document has DocBreak = Y, continuation pages leave it blank.
• PageCount appears on the document's first page.

ABC000001,VOL001,\IMAGES\001\ABC000001.tif,Y,,,3
ABC000002,VOL001,\IMAGES\001\ABC000002.tif,,,,
ABC000003,VOL001,\IMAGES\001\ABC000003.tif,,,,
ABC000004,VOL001,\IMAGES\001\ABC000004.tif,Y,,,1

(A 3-page document ABC000001–003 then a 1-page document ABC000004.)

Data rules

• DAT and OPT must agree on Bates: BEGBATES/ENDBATES in the DAT must match the document's page range and DocBreak boundaries in the OPT.
• Family integrity: BEGATTACH=parent BEGBATES and ENDATTACH=last child ENDBATES for every member of a family; all members share the family range.
• Dates use a single agreed format (commonly MM/DD/YYYY); keep date and time in the agreed fields; normalize time zone per the ESI protocol.
• Paths are relative to the production root and must resolve to the actual native/text/image files; use the agreed path separator.
• Field order in the data rows must match the header row exactly; every row has the same field count.

Worked example (DAT header + one row — delimiters shown as ¶ / þ)

þBEGBATESþ¶þENDBATESþ¶þBEGATTACHþ¶þENDATTACHþ¶þCUSTODIANþ¶þFROMþ¶þSUBJECTþ¶þDATESENTþ¶þNATIVEPATHþ¶þPAGECOUNTþ
þABC000001þ¶þABC000001þ¶þABC000001þ¶þABC000002þ¶þDoe, Janeþ¶þjane@acme.comþ¶þQ1 forecastþ¶þ01/15/2025þ¶þ\NATIVE\001\ABC000001.msgþ¶þ1þ

(Email ABC000001 with a one-page attachment ABC000002; family range BEGATTACH ABC000001 → ENDATTACH ABC000002.)

Validation checklist

• Receiving party's load-file spec confirmed (field list/order, delimiters, date format, path style, time zone)
• DAT header row present; every data row has the same field count and order as the header
• Concordance delimiters consistent (field ¶ 20 / quote þ 254 / multi-value ® 174) or the agreed alternates
• BEGBATES/ENDBATES match the OPT page ranges and DocBreak=Y boundaries
• Family fields BEGATTACH/ENDATTACH set for every family member
• NATIVEPATH/TEXTPATH/image paths resolve to real files; hashes present
• Dates in the single agreed format; confidentiality designations populated if produced
• Test-loaded into the target platform before bulk delivery

Last updated: 2026-05-31 — DAT/OPT is an industry convention; confirm the exact field set, delimiters, date/time format, path style, and the OPT layout against the receiving party's load-file specification / ESI protocol before use.