I suspect that most of the CSV issues I've encountered were produced by ad-hoc writers and parsers embedded in applications rather than serious attempts to impl

I suspect that most of the CSV issues I've encountered were produced by ad-hoc writers and parsers embedded in applications rather than serious attempts to implement a CSV library. Behaviors I've encountered during various integrations: - Values in most columns are escaped, but a few are not. (You have to count commas from both ends of the line and then log a warning and make a guess if there are too many commas.) - ASCII whitespace is url-encoded (why?) but no other characters are. - Columns without double quotes can only contain digits. - Double commas are used as the field separator because they didn't want to implement quoting. (Some of the fields came from user input on a web page, and I prayed for them to hit a double comma and learn the error of their ways, but it never happened. I think their front end developers were sanitizing for them.) - And my favorite, no quoting was supported at all, double quotes were left unquoted, commas were stripped from values when writing, and when reading, fields were compared against a list of mappings like "Acme Inc." -> "Acme, Inc." to restore the commas.