How to number exhibits: C-1, R-1 and the rules behind them

Start with the procedural order

Exhibit numbers are how everyone in a case finds a document: counsel in their briefs, witnesses in their statements, the tribunal or the judge at the hearing and in the decision. A numbering system chosen in a hurry and changed halfway through costs hours of cross-checking and invites errors into the record.

Before you number anything, check what governs. In arbitration the rules are usually set out in the first procedural order; in court, in the procedural rules, the local rules or the individual judge’s practices. Where nothing is prescribed, follow the conventions below — they are what tribunals and courts expect to see.

Party prefixes: C-1 and R-1 in arbitration

In international arbitration each party numbers its own documents behind a letter prefix: C- for the claimant, R- for the respondent. ICSID’s model first procedural order uses C- and R- for factual exhibits and CL- and RL- for legal authorities, numbered consecutively throughout the proceeding, with the number on the first page of the document and in its file name. Tribunals under other rules commonly adopt the same pattern.

Padding is a matter for the order, too. ICSID’s template starts at C-0001 so that files sort correctly in a folder; many tribunals are content with C-1. Whichever form you use, use it everywhere — in citations, file names and the index.

Claimant and defendant numbering in court

Courts have their own habits, and they vary more than arbitral practice does:

• England and Wales. Exhibits to a witness statement or affidavit are identified by the witness’s initials and a number, such as “JS1”. Where the same witness makes several statements, Practice Direction 32 asks for the exhibit numbers to run on consecutively rather than start again with each statement.
• United States. Practice is set court by court and often judge by judge. Some judges require the plaintiff to mark exhibits with numbers and the defendant with letters; others give each side a block of numbers — the District of Arizona’s instructions give Plaintiff 1–80 and Defendant 100–180 as an example.
• Germany. By convention the claimant’s exhibits are Anlage K 1, K 2 (for Kläger) and the defendant’s Anlage B 1, B 2 (for Beklagter).

Number continuously across submissions

Exhibit numbers run through the whole proceeding, not per submission. If the Statement of Claim ends at C-41, the first new exhibit in the Reply is C-42. Restarting at C-1 gives two documents the same address.

Statement of Claim: C-1 to C-41 · Reply: C-42 to C-77

Two rules follow. First, a document already on the record keeps its number: if the respondent filed the contract as R-3, cite R-3 rather than exhibiting it again as C-78. ICSID’s model order asks the parties to file documents only once, and the District of Arizona tells parties not to mark a document the other side has already marked. Second, a number once filed is never reused. If an exhibit is withdrawn, leave the gap and mark it “withdrawn” in the index.

Sub-numbering: C-5.1, C-5.2

Some documents belong together: an email and its attachments, a run of monthly invoices, a set of photographs. There are two clean ways to handle them.

• One exhibit, paginated. File them as a single exhibit and number its pages consecutively. ICSID’s model order expressly allows several documents on the same subject in one exhibit, each page numbered separately and consecutively.
• Sub-numbers. Give the parts their own sub-numbers so that each can be cited alone. US courts that allow sub-parts often use letters instead (3a, 3b).

C-5.1 Email of 3 May 2023 · C-5.2 Its attachment

Agree sub-numbering with the other side or the tribunal before relying on it, and never use it to squeeze a new document between two filed exhibits — that is what the next free number is for.

Exhibits, authorities and testimony are separate series

Keep three kinds of material apart, each with its own numbers:

• Exhibits prove facts: the contract, the letters, the board minutes.
• Legal authorities prove the law. ICSID describes them as sources of law — the text of the law, doctrine or jurisprudence — numbered behind CL- or CLA- and RL- or RLA-. Decide borderline cases once, for example a decision in a related proceeding, and stay consistent.
• Witness statements and expert reports are evidence in their own right. Many orders number them CWS-/RWS- and CER-/RER-, either sequentially (CWS-1) or by the witness’s name (CWS-Jones), with a second statement marked as such.

Exhibits attached to a witness statement or expert report may continue the party’s main series or carry their own numbers; ICSID’s template, for instance, uses the witness’s initials (MJ-0001). Follow the order — and see arbitration exhibit conventions for more on practice before tribunals.

Renumbering pitfalls

Before filing, numbering in order of first citation is convenient: the reader meets C-1 first, C-2 second. The trouble starts when the draft changes and the numbers are moved by hand. The usual casualties:

• a footnote, a witness statement or an expert report still cites the old number;
• the index and the file names were not updated together with the brief;
• the same document ends up under two numbers, or two documents under one;
• a number cited in the brief does not appear in the index at all.

Once a submission is filed, treat its numbers as fixed. The other side, the witnesses, the transcript and the tribunal will all cite them. Renumber only before filing — and check every cross-reference when you do.