Hidden characters

Flagged	Fix
a zero-width space, zero-width non-joiner, word joiner, or Mongolian vowel separator	remove the zero-width character
a zero-width joiner outside an emoji sequence	remove the zero-width joiner
a byte order mark after the first character	remove the byte order mark
a soft hyphen or non-breaking hyphen	use -, or remove the soft hyphen
a narrow no-break space or figure space	use a plain space
a Unicode tag character	remove the tag character, it can hide text
a variation selector other than the emoji and text selectors	remove the variation selector, it can hide data
a bidirectional control character	remove the bidi control
ChatGPT citation markers: cite followed by turn0search0, or contentReference followed by an oaicite index	remove the citation residue

Anthropic’s text watermark adds no characters, so this pack cannot see it. In a code file the pack reads the whole file, string literals included, through the code scope. U+00A0 is left out: npm READMEs carry it 5.6 times per 10,000 words. A zero-width joiner inside an emoji sequence and tag characters after the black flag (subdivision flags) stay unflagged. A right-to-left project lists hidden-characters in excludePacks or drops the bidi row with its own pack.