The Media Log
It's also referred to as a tracking spreadsheet or delivery manifest, but the "media log" is one of the most important pieces of paper in your Chain of Custody. If the sending party doesn't provide a media log to accompany a piece of delivered data, don't process the data! If they push back and say, "Can you guys just fill out the log based on what's on the DVD?", don't do it. You have no way of knowing what's on the disc. There have been many, many instances where the sending party forgot something that they "intended" to send. There's also the event that the sending party accidentally copied material to the media that was collected for another matter altogether. The log is a tool to confirm the nature and validity of contents contained therein. Months can go by and a question could eventually arise, "Didn't you process Custodian ABC hard drive data in batch XYZ? It was supposed to be on the DVD that we sent you", or more egregiously, "Why am I seeing Custodian ABC data in the repository? He has absolutely nothing to do with this case!" The media log allows you to address discrepancies immediately.
You can process the material that is sent "as-is" as long as you accept all assumptions that go along with it. You can analyze the contents beforehand and can report any anomalies, but there's no way of confirming for sure the accuracy or thoroughness of the delivery. In other words:
Accuracy: Are all the custodian sources there?
Thoroughness: Was all the data copied? If you see an empty source directory for Custodian ABC's network share, should you be concerned?
I know we've been in the business for a long time, so these risks are semi-obvious, but it doesn't hurt to reiterate at the outset of a new project. The workflow and standards that you enforce beforehand really set the stage for a successful engagement.
Repopulating Dupes
Are you required to repopulate duplicate documents in your production? Be aware that you may be left with unmarked documents. Not every tool propogates reviewer markings to repopulated duplicate documents. Not only that, repopulation may not even work unless the "duplicate owner" custodian is included as part of the production.
While deduplication may seem like a great way for you to reduce the number of documents that you ultimately have to review, understand how your decision could create downstream headaches on the production end of the pipeline. You
may need to post-process the production before you ship it out the door.