If I recall correctly, you can have empty fields and the way you actually escape a double quote is as "" instead of \". In other words, these are allowed:

1,"Hello world",,2
2,"""Hello world""",,2
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I also believe that if the field contains a double quote, then the entire field must be enclosed in double quotes so escaping rules could apply. There are more rules, but they're mostly allowed values and input record separator issues more than anything else, but that's just for saving and verification that the file you have is really CSV. I think you can read more about them at the end of the documentation here.

Of course, this is only if you want valid CSV or CSV produced by programs such as Excel and whatnot.

Hope this helps.