Prince Frederick of Orange to his brother, London, 7 May 1795

TASK: take a partial decipherment further: Prince Frederick of Orange to his brother, London, 7 May 1795
This page: https://dbourdeau.github.io/cyphersolver/further/r2242.html

You are helping a public research project finish reading historical cipher letters. This one is read in part:
the key works, but some pieces are still open. Your job is to close one or more of the open gaps below.

THE READING
  Write-up:   https://dbourdeau.github.io/cyphersolver/r2242.html (read it first: how the text was read, the key, the reading)
  Date:       1795
  Outcome:    external key matched · partial
  Read now:   95.9% of the deciphered cipher tokens give sense (pieces below may be untouched)
  Files:      https://github.com/dbourdeau/cyphersolver/tree/main/targets/r2242 (NOTES.md, key, transcription, reading, scripts)

OPEN GAPS (from NOTES.md, "## Remaining gaps")
  1. [no-key-material: needs a new source] signs that occur twice (plain Δ: p3 l11 and p4 l1; %: p3 l10 and p4 l4; crossed diamond, value voor at I only) - blocker: no-key-material; no value fits both occurrences, retried 2 and 3 Oct 2026
  2. [no-key-material: needs a new source] nineteen signs that occur once (T-bar, S-stroke, square bracket, H with P, dagger, V-with-cross, C-hook, crossed o, vertical bracket, x mark, Δ with tail, H with loop, ψ, P.S. S / crossed ø / ⊖, and X, &, + whose context-only values weinig / Engeland / mogelyk are counted unread) - blocker: no-key-material; a single context cannot fix a word sign, none occurs in R1892, no key sheet, not in print
  3. [illegible: needs a new source] two tokens under ink blots (p3 l12 crossed circle, P.S. sign after "landig") - blocker: illegible; the photocopy is blotted at both places
  4. [no-key-material: needs a new source] P.S. "Dankaert" unidentified - blocker: no-key-material; the name is spelled out in the square, only its identity is unknown

ALREADY TRIED (from NOTES.md, "## Escalation")
  [x] siblings: R1892 (same key) used; its signs pooled with R2242's on 2 Oct 2026 (Λ = dat confirmed by three R1892 contexts; R1892 phi, S, Y-cross, x and cross do not take R2242's values); R2236/R2237/R2239 (hereditary1796) use a different numbered word list and share no signs
  [x] clear-pages: p1 clear text under the cipher used as crib; p2 clear letter read
  [x] known-keys: R1892 key applied unchanged
  [x] print: searched 2 Oct 2026 - Colenbrander, Gedenkstukken I (1789-1795) and II (1795-1798), full text on resources.huygens.knaw.nl/retroboeken/gedenkstukken, for Grasveld, Sitter, Blaauw, Robespierismus, gebraaden, persisteeren, saamenhang, gedimitteerde, verstrooid, Banquier, rassemblement, "Prins Frederik aan", ratificatie; GS II pp. 834-841 (May-July 1795 letters) read: the letter is not printed; GS I p. 655 and p. 678 confirm the envoys De Sitter and Van Grasveld and the ministers Blauw and Meyer
  [x] key-rebuild: word signs extended from context, 30 Sept 2026 (uit, van, Frankrijk, om) and 2 Oct 2026 (dat, daar, naar, zonder, zijn, weinig, al, Engeland, mogelyk, voor, ik, dez-; flagged D and the interlinear inverted D = van)
  [x] retry: 2 Oct 2026 - p3 l1 and p4 l8 re-transcribed at full resolution and rerun with apply.py; p3 l2 end, p4 l6, p3 l11 and five doubtful pairs re-read; every unread sign retried against the extended key, R1892 and the printed context, and regraded (table above). 3 Oct 2026 - every token failing the sense test re-checked (measure_sense.py --show); p3 l6 corrected; sign grades re-examined under the forced-context rule; measured strict 95.9%

STEPS
0. Set up. If you can run a shell, fork and clone the repository and work inside it:
     git clone https://github.com/dbourdeau/cyphersolver.git
   Then read, in this order: CONTRIBUTING.md (how a contribution is sent and credited); README.md, sections
   "Repository layout" and "Conventions" (how readings are measured and named); targets/r2242/NOTES.md in full, and the
   key, transcription and reading files it names; lang/README.md (shared language models).
   Work in targets/r2242/. Add your findings to NOTES.md under a dated heading without rewriting what is there, and
   update the "## Remaining gaps" line of every gap you close. Keep WORKLOG.md there: one dated line per step
   (hypothesis, value tried, solver run, crib, control), failures included. Do not edit docs/ (the site is generated).
   If you cannot run a shell, fetch the files from the links above and keep your work in files you send with the issue.
1. Pick a gap. Start with the ones marked "doable now" (open-codes, not-attempted, left-open): the images and the key
   are online, so they need only work. A gap marked "needs a new source" (no-key-material, too-short, illegible,
   needs-physical-access) can be closed only by something new: a key
   or a deciphered sibling found elsewhere, a better image, a printed edition or calendar, a photograph from the archive.
   For those, search for that material first, and say where you looked even when you find nothing.
2. Start from the existing key and transcription in the folder. Do not rebuild the key from scratch, and do not
   re-read parts that are already read unless you find an error in them.
3. For a code group or sign value: list every place the group occurs, show how each reads with the value you propose,
   and say what still does not fit. For a passage: re-read it at the image and give the folio and line. For a missing
   letter or leaf: say where it is held and how it can be reached.
4. Measure again. Apply the key to the whole text, write the reading file, and count the share of cipher tokens that
   give sense (not an estimate). The reading is "complete" only when (1) at least 95% of its cipher tokens give sense;
   (2) no gap is left untried; (3) every letter in it is covered; (4) what stays open is scattered code groups or names,
   or pieces blocked from outside. Otherwise it stays "partial": say which gaps are still open and why.
5. Be honest. Mark every uncertain word with [?], leave unread groups as their numbers or signs, and never fill a gap
   with a plausible guess. A gap retried and still open, with what was ruled out, is worth reporting.

REPORT BACK
With a clone: open a pull request with your changes to targets/r2242/. Say in the description which gaps you worked on,
  the share read before and after, and how you want to be credited (name, initials or handle, and a link).
Without one: open an issue: https://github.com/dbourdeau/cyphersolver/issues/new?template=further-reading.yml&title=Further+reading%3A+r2242&page=r2242.html
  Give the write-up, the gap you worked on (its line in Remaining gaps, or the code group, folio and line), what you
  propose, the evidence (every occurrence, the images or sources), the share read before and after, your step log,
  and the tools and AI model you used.
If you cannot open issues or pull requests, write this report for your human to send. Credit goes to the person who sends it.