…describe the nature of the documents … not produced or disclosed … in a manner that, without revealing information itself privileged or protected, will enable other parties to assess the claim.
Fed. R. Civ. P. 26(b)(5)(A)
Read what it does not say. No fields, no format, not even the word log. The test is whether the other side can assess the claim. Everything else is convention.
Why logs get challenged
Two reasons, and they are the same mistake. The description says “privileged communication” on 400 entries, so the other side cannot assess anything. Or the log for the second production contradicts the log for the first, because both were built by hand from a spreadsheet, months apart, by different people. A log written per production drifts.
The log as a query
A defensible log is a set of facts plus a justification. The facts (date, author, recipients, document type, which production it was withheld from) are already in the platform once coding is done. The justification (“legal advice from outside counsel re the Henderson dispute”) comes from a protocol you set, and it is attached to the document, not to the log.
If the log is a query over those two things, every production's log is derived from the same facts and the same justifications. Withhold a document from the third production and it appears with the justification it already carries. Change a justification and every log that cites it updates. Nothing drifts, because nothing is copied.
How Marbury does it
A production deposits the facts. A protocol you write tells the AI how to describe each withheld document, or which preset to apply based on its privilege basis. Ask for the log and the agent derives the withheld set, applies the protocol, and renders it under your column names. A supplemental log costs almost nothing.