The newer GPT-o3 and GPT-o4 mini models appear to be embedding special character watermarks in generated text. However, removing these watermarks is relatively simple, making this seem more like a short-term measure than a long-term solution
What’s displayed in the screenshots are typographically relevant variations of the whitespace. 0x00A0 is the non-breaking space, and 0x202F is a narrow whitespace. Both have their own Wikipedia pages where you can look up what to use them for. And while browsers may display them the same as a regular whitespace, because they just suck at typography, the same is not true for word processing or layout software.
Granted, while they can be detected and used as watermarks, although I regularily used them in my text formatting software as well. The resulting text flows better and will not be wrapped in illogical ways. So I don’t think they are intended as watermarks, and I also don’t think they will be going away again. It’s just such a tremendous improvement of the output.
What’s displayed in the screenshots are typographically relevant variations of the whitespace. 0x00A0 is the non-breaking space, and 0x202F is a narrow whitespace. Both have their own Wikipedia pages where you can look up what to use them for. And while browsers may display them the same as a regular whitespace, because they just suck at typography, the same is not true for word processing or layout software.
Granted, while they can be detected and used as watermarks, although I regularily used them in my text formatting software as well. The resulting text flows better and will not be wrapped in illogical ways. So I don’t think they are intended as watermarks, and I also don’t think they will be going away again. It’s just such a tremendous improvement of the output.