Electronically stored information is the category the Federal Rules use for any information created or stored in digital form that is discoverable in litigation. It is deliberately broad — email, chat, documents, databases, cloud records, phone data and system logs all qualify, whatever the format or medium.
Why the definition is deliberately vague
The drafters chose breadth over precision, and they were right to. Any list of formats written in 2006 would have omitted Slack, Teams, ephemeral messaging, collaborative documents with revision histories, and whatever arrives next. Defining ESI by its digital nature rather than by enumeration is what has let the rule survive twenty years of platform change.
The practical consequence is that arguing a category of data is not ESI almost never works. The productive arguments are about accessibility, proportionality and burden, not about whether the thing counts.
Not-reasonably-accessible is not the same as irrelevant
The Rules distinguish ESI that is reasonably accessible from ESI that is not — typically legacy backup tapes, deprecated systems, or data requiring specialist recovery. A party need not produce from not-reasonably-accessible sources absent good cause, but it must identify them, and the duty to preserve is not suspended merely because production would be burdensome.
That identification requirement is regularly overlooked. Staying silent about a legacy system because retrieving from it would be expensive converts a manageable burden argument into a preservation problem.
Where ESI actually lives now
The centre of gravity has moved, and collection practices have not entirely followed:
- Collaboration platforms. Chat, channels and threads, where the candid discussion happens and where retention defaults are shortest.
- Cloud documents with revision history. The current version is one document; the edit history is often the evidence.
- Structured systems. CRM, ERP, ticketing and financial systems, where the relevant material is a query result rather than a file.
- Mobile. Messages, location data, app records — increasingly the only place a conversation exists.
- System and audit logs. Rarely requested and frequently decisive, because they record activity rather than content.
Form of production matters more than it sounds
ESI can be produced natively, as images with a load file, or as paper-equivalent output that strips everything the digital form carried. Producing a spreadsheet as a TIFF destroys the formulas; producing an email as a PDF discards the header metadata that establishes routing.
Requesting parties may specify a form, and disputes about it are far cheaper resolved in an ESI protocol at the outset than by motion after a production has been made in the wrong format and has to be redone.
The practical instruction
When scoping preservation, the useful question is not "what documents exist" but "what systems record activity relevant to this dispute." The first question produces a folder of documents. The second produces the logs, the metadata and the platform records that usually decide what actually happened.
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