Comma-separated Values - Lack of A Standard

Lack of A Standard

The name "CSV" indicates the use of the comma to separate data fields. Nevertheless, the term "CSV" is widely used to refer a large family of formats, which differ in many ways. For example, many so-called "CSV" files in fact use the tab character instead of comma (such files can be more precisely referred to as "TSV" for tab separated values); some allow or require single or double quotation marks around some or all fields; and some reserve the very first record for a list of field names.

A particular problem is that in some countries, it is very common to write the decimal point as a comma instead of period. For example, pi would be written as 3,14159. This makes the comma a poor choice for field-separator in many locales. Other implementation differences include handling of more commonplace field separators (such as space or semicolon) and newline characters inside text fields.

Such lack of standardization can cause problems for data exchange based on so-called "CSV" files. One solution is to rely on a standard, such as that proposed by RFC 4180. The more common but technically less satisfactory solution is to rely on human intervention: because CSV files are plain text, humans can view and diagnose most common variants using a text editor.