

Do you have more concrete examples? I’m reasonably familiar with OpenXML, and seeing the date issues in microsoft systems (Excel having the same bug that considers 1900 a leap year, to stay compatible with Lotus Notes), i can imagine them redefining everything just to be in full control ^^'…
I don’t think it has much to do with how “complex or not” it is, but rather how common it is.
It can completely fail on very simple things that are just a bit obscure, so it has too little training data.
And it can do very complex things if there’s enough training data on those things.