Bidirectional marks
RIGHT-TO-LEFT MARK (U+200F)
The mirror of U+200E: an invisible character with strong right-to-left direction, used to resolve ambiguity in mixed-direction text.
- Codepoint
U+200F- Category
- Bidirectional marks
- Removed by default
- When free-floating
- Governing option
- Bidi marks
--bidi - Can be load-bearing
- Yes
Where it comes from
Hebrew and Arabic documents, localisation pipelines that wrap variables defensively, and the same LRM/RLM steganography scheme.
Why it matters
It is invisible and it changes layout, so a stray one in a left-to-right paragraph can nudge punctuation to the wrong side of a line for no visible reason. In an English paragraph it is pure padding.
Before and after
In an English sentence the mark only moves the full stop around; there is no right-to-left text for it to help.
The character is shown as a labelled chip so you can see where it sits. In your text it draws nothing at all.
When it is legitimate
Next to right-to-left text — most often after a variable or a number embedded in an Arabic or Hebrew sentence, to stop the punctuation drifting.
How to remove it
Removed by the default pass when no neighbour is right-to-left; kept and reported when one is. `--bidi` removes it in both cases.
Is it an AI watermark?
Used to hide data — not a watermark
No. Half of a two-symbol invisible alphabet, and also a legitimate bidi hint. Neither reading involves a language model.
A known carrier for deliberately hidden payloads. Someone put it there on purpose, which is a different question from who wrote the words.
Questions
Why does my full stop jump to the wrong side?
Punctuation takes its direction from the surrounding text. A stray right-to-left mark changes that context, which is exactly the bug these marks are meant to fix — and cause.
Is Arabic text safe?
Yes with the defaults: a mark adjacent to Arabic is kept. Only `--bidi` removes it.
Check your own text
Paste anything into the cleaner to see every hidden character it contains, with position, codepoint and what happens to each one. Nothing is uploaded.