I wonder if it is possible to implement a watermark via patterns of Oxford comma occurrences and similar linguistic styles that would fit into a simple character set.
It's possible to implement a purely informational watermark lots of ways, but no such watermark long survives wide awareness of its use. To know how it works is to know how to defeat it.
This specific scheme is also not remotely novel; I once saw it implemented, something like six or eight years back, in an effort to quell leaks to an industry rag with a habit of posting paragraph-length excerpts verbatim. They also did this with some of the watermarked emails, having stripped the watermarking whitespace before publication.
> I wonder if it is possible to implement a watermark via patterns of Oxford comma occurrences
This would be a glaring stylistic inconsistency in every text produced with a watermark. You could just as well implement a watermark by doing automated thesaurus replacements on certain of the words and using the index of the selected entry as a code.
A watermark that deeply unnerves everyone who reads the text can carry information, but it tends to render the tool itself unfit for purpose.
This specific scheme is also not remotely novel; I once saw it implemented, something like six or eight years back, in an effort to quell leaks to an industry rag with a habit of posting paragraph-length excerpts verbatim. They also did this with some of the watermarked emails, having stripped the watermarking whitespace before publication.