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3. MIME Type Registration of text/csv

This section provides the media-type registration application (as per RFC 2048 [1].

To: <[email protected]>

Subject: Registration of MIME media type text/csv

MIME media type name: text

MIME subtype name: csv

Required parameters: none

Optional parameters: charset, header

Common usage of CSV is US-ASCII, but other character sets defined by IANA for the "text" tree may be used in conjunction with the "charset" parameter.

The "header" parameter indicates the presence or absence of the header line. Valid values are "present" or "absent". Implementors choosing not to use this parameter must make their own decisions as to whether the header line is present or absent.

Encoding considerations:

As per section 4.1.1. of RFC 2046 [3], this media type uses CRLF to denote line breaks. However, implementors should be aware that some implementations may use other values.

Security considerations:

CSV files contain passive text data that should not pose any risks. However, it is possible in theory that malicious binary data may be included in order to exploit potential buffer overruns in the program processing CSV data. Additionally, private data may be shared via this format (which of course applies to any text data).

Interoperability considerations:

Due to lack of a single specification, there are considerable differences among implementations. Implementors should "be conservative in what you do, be liberal in what you accept from others" (RFC 793 [8]) when processing CSV files. An attempt at a common definition can be found in Section 2.

Implementations deciding not to use the optional "header" parameter must make their own decision as to whether the header is absent or present.

Published specification:

While numerous private specifications exist for various programs and systems, there is no single "master" specification for this format. An attempt at a common definition can be found in Section 2.

Applications that use this media type:

Spreadsheet programs and various data conversion utilities

Additional information:

  • Magic number(s): none
  • File extension(s): CSV
  • Macintosh File Type Code(s): TEXT

Person & email address to contact for further information:

Yakov Shafranovich <[email protected]>

Intended usage: COMMON

Author/Change controller: IESG