FuckMark is a UTF-8 command that inserts hidden Unicode into ordinary English ASCII text without changing what you see.
On confirmation-scale GPT-2 / SynthID tests, transformed text was not flagged, visible words stayed identical, and output was deterministic.
Website: mark.q1z.org · License: MIT
Python 3.11 or newer. From this repository:
python3 -m venv .venv
.venv/bin/python -m pip install .
.venv/bin/fuckmark --version
That prints FuckMark 0.4.0. v0.4.0 wheel SHA-256: 5a6ac62c8bb8d7ddd9e5bc9cb6cee6e3eb181ac5f397b4a6645ef86468ee932f. See docs/install.md. Do not pipe https://d.q1z.org/mark into a shell.
fuckmark
Paste or type text, then a line that is only :done. The result is copied to the clipboard. You still read the same words; the hidden payload is not printed.
printf 'I do not agree.\n' | fuckmark
fuckmark "I do not agree."
fuckmark notes.txt -o notes.fm.txt
printf 'I do not agree.\n' | fuckmark --visible
Pipes and files write the payload to stdout. fuckmark --help is enough to start.
VISIBLE(original) == VISIBLE(transformed). FuckMark only inserts U+034F and U+FE00 after eligible ASCII letters. It does not contract, paraphrase, homoglyph, or add spaces.
Supported input: tab, newline, carriage return, and ASCII space through tilde. Other Unicode is returned unchanged. Only UTF-8. URLs, code spans, paths, and similar machine text are left intact.
| Check | Result |
|---|---|
| Unmodified watermarked text still detected | 188/192 |
| Transformed text after required sanitizers | 0/192 |
| Transformed unwatermarked text | 0/192 |
| Exact visible text | 192/192 |
| Transformed text after UnicodeSanitizer | 0/192 |
Google synthid-text 30-key GPT-2 transformed text: 0/192.
This does not remove every AI watermark. It is not a claim against unknown, proprietary, or future detectors.
Stripping combining marks or default-ignorable characters restores the source. English ASCII only. Cap 192 insertion sites.
Eligible ASCII letters receive an alternating pair of invisible characters (U+034F, then U+FE00). The public command is fuckmark / FuckMark / Fuckmark.
Frozen evidence, hashes, and protocols: docs/research.md. Product contract: docs/product-contract.md. CLI: docs/cli.md.
python -m pip install -e ".[dev]"
python -m pytest
MIT. See LICENSE.