It seems to have been purely stylistic, but that's still unacceptable, especially since it broke conventions of the field.
"My curse upon anyone who, in future editions of my works, knowingly changes anything in them, be it a sentence, or even just a word, a syllable, a letter, a punctuation mark."
One example is the Jewish lawbook "Toldos Adam V'Chava"[1]. Although many old religious texts have been reprinted with clear modern typesetting, no-one wanted to re-typeset this until recently because of the curse.
On the plus side, we know exactly what the author wrote 800 years later, even if it is hard to read.