[boogheta]

It sounds to me like as often the problem here is Excel, not CSV

[pasc1878]

Yes but in practice CSV is defined by what Excel does.

As there is no standard to which Excel conforms as it predates standards and there would be an outcry if Excel started rejecting files that had worked for years.

[imtringued]

There is a common misconception here. You can import CSV files into an excel sheet. You cannot open a CSV file with excel. That is a nonsense operation.

[melagonster]

Excel do not ask the user whether they want to import file, and tell user their file was broken.

[IanCal]

Clients don't particularly make the distinction, and in a way nor should they - they can't open your file.