One example that will kill loading a csv in excel beyond the usual dates problem. If you open in excel a csv file that has some large id stored as int64, they w

One example that will kill loading a csv in excel beyond the usual dates problem. If you open in excel a csv file that has some large id stored as int64, they will be converted to an excel number (I suspect a double) and rounded. Also if you have a text column but where some of the codes are numeric with leading zeros, the leading zeros will be lost. And NULL is treated as the string "NULL". I am aware you can import a csv file in excel by manually defining the column types but few people use that. I'd be fine with an extension of the csv format with one extra top row to define the type of each column.