A party withholding responsive material on privilege grounds must describe it sufficiently to enable the claim to be assessed.

Traditional document-by-document logs state the date, author, recipients including copies, document type, and a description of the subject matter sufficient to show the basis for the privilege without revealing its substance.

Metadata and categorical logs. Courts increasingly permit categorical logs grouping similar documents, or metadata-based logs generated from the review platform, particularly for large productions. Agreeing the format in the ESI protocol avoids a fight later.

Common defects. Descriptions that recite legal advice without indicating the subject; omission of whether an attorney was involved and in what capacity; failure to identify which of several claimed protections applies; and treating communications with non-lawyers as privileged without explaining the connection to legal advice.

Attachments are logged separately from parent emails, since a non-privileged attachment does not become privileged by being sent to counsel.

Timing. Logs are due with the production or on an agreed schedule. Substantial delay risks waiver, and courts have found waiver where a log was withheld for months without explanation.

In-house counsel communications require care, since business advice from a lawyer is not privileged. Identifying the legal purpose in the log entry is what supports the claim.