How to contribute

01 Five kinds of contribution

A solution to a cipher already in the ledger

Any target in the catalogue, any write-up marked not solved, and any open item in the notes. Send:

• the target (catalogue number, write-up page or folder name) and the documents covered (shelfmark, folio, DECODE record);
• the key: the sign-to-value table, the code groups you have values for, and the nulls;
• the full texts of every document you claim as read, in full or in part: the complete transcription of the ciphertext and the complete decipherment, line by line against it, with the passages you are unsure of marked. They are shown on the write-up, inline or linked when long, so that the text can be used by historians and the reading judged by those who worked on it before you;
• the key, in full if you recovered, extended or corrected it, and if you can, a short summary of what each document says and its historical context;
• how the key was obtained: from the ciphertext alone, from plaintext beside it or elsewhere, from an existing key (whose), or from an existing decipherment. This sets the method shown on the write-up;
• whether the reading was already published anywhere, as far as you know.

A fuller reading of one left partial

Many write-ups are read only in part. Their notes list what is still open and why: code groups with no value yet, lines hard to read on the images, letters for which no key is known, pieces that need the original in the archive. The list of readings to take further shows each one with its open gaps, the most workable first. You do not need to finish a reading to help: one step is enough. Send:

• the write-up and the gap you worked on (the line in its notes, or the code group, folio and line);
• what you propose: a value for a code group, a corrected key value, a new reading of a passage, a key or a clear copy found elsewhere, a reading made from the original in the archive;
• the evidence: every place the value occurs and how it reads there, the image or source you worked from, and anything that still does not fit.

Each step is credited on the write-up, and the reading’s extent is re-measured with it.

A visit or a request to an archive. Some gaps can only be closed from the original or from a book the project cannot reach: a line lost in the binding, a leaf never photographed, a decipherment in a volume that was not digitised, an edition behind a login. They are listed by archive and city on To the archive. Take one on with the “I can do this” link (it opens the archive-request form with the request filled in), then send the photographs, the reproduction or the passage. A visit that finds nothing is reported and credited too.

A new unsolved cipher

A ciphered document with no known decipherment that is not in the ledger yet. Send:

• the archive, shelfmark and folio, and a link to the images (Gallica, DECODE, the archive’s viewer) or the images themselves if you may share them;
• date, sender and recipient if known, and the language you expect;
• what you know of its status: listed as undeciphered where, any key or decipherment you have looked for;
• a transcription, if you have one. It is not required.

A new cipher with its solution

Both of the above: the document, then the key, the full transcription and decipherment, and how you obtained them. Results that have never been published are welcome; say whether they may be shown here in full or only noted.

A verification of a reading already here

The verification queue lists the readings whose key was recovered or matched here and that no one outside the project has checked. Take the images and the key from the write-up, decipher a passage yourself (a paragraph is enough), and report:

• which passage, and which images you worked from;
• where your reading agrees with the write-up, and every place it does not;
• any key value you would change, with the evidence.

A check that finds errors is as useful as one that confirms. Both are credited.

02 How to send it

03 How credit works

• On the write-up. The page names every contributor under its outcome line, with what each did: solution, new cipher, verification, key correction, transcription, identification, a pointer to a source, or the key or decipherment the reading used.
• On the contributors page. Credits are added up by person and by kind, each count linking to the write-ups. The top contributors are listed on the front page.
• Your name, your way. Say how you want to be named (full name, initials, a handle) and where your name should link.
• Unpublished work. An earlier solution you never published is noted as unpublished, and shown in full only with your agreement.
• Earlier scholarship. Keys and decipherments taken from editions, archives and databases are credited to their makers too, in a separate list, so living contributors are not ranked against the nineteenth century.

04 What happens next

• The contribution is checked against the images: the key applied to the ciphertext, the decipherment read for sense.
• It is filed in the target’s folder with its key, transcription and notes, given a method and an extent, and written up or added to an existing write-up.
• Where the target is on DECODE, the corrections and the decipherment are queued for the DECODE record, credited to you.
• The ledger also feeds a study of how language models perform against historical ciphers. A result you contributed is marked as yours and is kept out of the model’s figures.
• Tools are your choice, including AI. Say what you used, and check the reading against the images before sending it.