Look at https://fr.wikipedia.org/w/index.php?curid=1265106&diff=106479359&oldid=106473232
to find the addition of hidden comments like this:
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Mr. Google says that this is caused by pasting contents from MS Word into (for example) e-mail messages.
Version: unspecified
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=69513
https://bugzilla.wikimedia.org/show_bug.cgi?id=61371