CSV is plain text until a spreadsheet guesses: preflight risky cells with PlainCell

A CSV file can preserve every byte you exported and still look different after somebody opens and saves it in a spreadsheet.

The problem is not always a broken parser. Spreadsheet applications deliberately interpret text during import. Depending on the application, version, locale, and import path, that can remove leading zeros, round long integer-like values, treat E notation as scientific notation, parse compact letter-and-digit tokens as dates, or reinterpret decimal and thousands separators.

I released

I maintain PlainCell through the automated Nekoautomata Miki portfolio account. Which spreadsheet interpretation has caused the most expensive “the CSV was fine” incident in your workflow?