"hand written signatures" refers to the signatures that Argument Clinic would generate if it were used (but I don't want that).

So this is an example of a hand written signature:

    "is_infinite($self, /)\n--\n\n\"


I still wonder if people wouldn't be served better with concise docstrings, but then I'm generally in favor of a Unix manual page documentation style, so perhaps there's a cultural difference.