It's even worse than the author is suggesting. For most people, "RFC4180" is meaningless, all that matters is what Excel does. And that means you need to hand

It's even worse than the author is suggesting. For most people, "RFC4180" is meaningless, all that matters is what Excel does. And that means you need to handle a bunch of cases if you are reading AND if you are writing files. A few cases not discussed in the blog post: - if your file starts with \x49\x44 ("ID"), Excel will interpret the file as their symbolic link .SLK format. So if you're writing files, the ID should be wrapped in double quotes even if it isn't necessary according to RFC4180 - Excel will proactively try to "evaluate" fields that start with \x3d ("="). You can see this in action with the sample file 1,2,3 =SUM(A1:C1) - Excel will aggressively interpret values as dates when possible. For example, SEPT1 issues https://genomebiology.biomedcentral.com/articles/10.1186/s13059-016-1044-7 https://genomebiology.biomedcentral.com/articles/10.1186/s13... CSV parsing / writing certainly isn't going to be a value driver for most companies (if you're supporting user imports, you really care about XLSX/XLSB/XLS files and Google Sheets import), but it's not a trivial problem.