Well the standard says to double the double quote to escape it. If you are seeing \" or even """ to escape a quote, then someone isn't following the standard.
I believe that the Swedish Klarna files uses ; but the Danish ones uses the comma + space. That only adds to the stupidity though, why not have just one format?
I have an function that I usually use in projects that counts , and ; on each line to determine which one is most likly beeing used in the file.
The most annoying thing I have found in csv files is the escape sign I would like it to be \" but very often I see """ as the escape for "