The IAU-FWG maintains the List of Registered Extensions. The list includes a brief summary of the extension type corresponding to each name, the developer, and the status of the extension (e. g., standard, under discussion, local).

Chronology of FITS Activities of the IAU and the IAU-FWG

July 1982

The IAU General Assembly endorses FITS, including the Random Groups format, as the recommended format for transport of binary data.

July 1982

Commission 5 forms a Task Group, headed by Preben Grosbol, to define and test a table extension to the FITS standard. The work of this Task Force resulted in a proposal for rules for generalized extensions to FITS and an ASCII Table extension for table and catalog data.

July 1988

The IAU General Assembly endorses the Generalized Extensions and ASCII Table Extensions agreements.

July 1988

The IAU FITS Working Group is formed under IAU Commission 5 by a resolution of the IAU General Assembly. Preben Grosbol and Don Wells are elected chairman and vice-chairman, respectively.

1 Jan 1990

The Floating Point Agreement, establishing IEEE 32-bit and 64-bit numbers as the standard FITS floating point data type, is approved by the IAU-FWG.

6 May 1994

The Physical Blocking agreement for FITS files on different media is approved by the IAU-FWG.

6 May 1994

The Image Extensions paper is approved by the IAU-FWG.

10 June 1994

The Binary Table Extensions paper is approved by the IAU-FWG.

18 August 1994

New IAU-FWG officers are elected: Don Wells (chair) and Ernst Raimond (vice chair)

11 Nov 1997

The Year 2000 DATExxxx keyword agreement is approved by the IAU-FWG.

12 Oct 2000

The NOST FITS Standard v2.0 is approved by the IAU-FWG.

18 Dec 2002

The World Coordinate Systems Paper I and Paper II are approved by the IAU-FWG.

21 July 2003

New officers of the IAU-FWG are elected: William Pence (chair) and Francois Ochsenbein (vice chair).

9 August 2004

The IAU-FWG endorses the proposal for 2 FITS MIME types ("image/fits" and "application/fits") and recommends that it be submitted to the appropriate Internet regulatory committees for approval as an Internet standard. The regulatory committees ultimately granted final approval for these 2 MIME types in RFC 4047 that was issued in April 2005.

9 August 2004

The creation of a 4th regional FITS committee, to represent astronomical institutions in Australia and New Zealand, is approved by the IAU-FWG. Mark Calabretta (CSIRO) serves as the first chairman of this new committee.

7 April 2005

The "variable-length array" facility in FITS binary tables, and the TDIMn = '(l,m,n,...)' multidimensional array keyword convention were approved by the IAU-FWG to be incorporated into the official FITS Standard document. These 2 features had previously been defined in the unofficial appendices to the Standard.

May 2005

Issued an update of the official FITS Standard document (version 2.1) to reflect the changes that were approved in the previous month.

18 August 2005

The World Coordinate Systems Paper III is approved as part of the FITS Standard by the IAU-FWG. This paper defines how to represent spectral coordinates in FITS.

8 December 2005

Three proposals to add support for 64-bit integers to the FITS Standard were approved by the IAU-FWG: 64-bit integer primary arrays and image extensions, 64-bit integer columns in binary tables, and 64-bit descriptor columns in binary tables.

26 April 2006

The HEALPix spherical coordinate projection was approved by the IAU-FWG as an addition to the other spherical projections defined in WCS Paper II.

June 2006

Established the rules and procedures for documenting existing FITS conventions in a new Registry of FITS conventions that is to be maintained on the FITS support office web site.

January 2007

Appointed a 5 member technical panel to draft changes to update and clarify the FITS Standard document. The last major revision to this document was in 1999.

July 2008

Formally approved the new 3.0 version of the FITS Standard document after a lengthy public review process.

December 2013

The 4 regional FITS committees (North America, Europe, Japan, and Australia/New Zealand) were officially disbanded, and the formal IAU-FWG voting rules were modified accordingly.

9 June 2014

Officially approved the paper by Rots et al. titled Representation of Time Coordinates in FITS. This paper continues the series of previous papers which defined the representations of world coordinate systems in the celestial (sky) and spectral dimensions.