(File last updated 12 February 1992 UT 2115)

                     Registered Extensions to FITS
                        IAU FITS Working Group
                            Preben Grosbol

Introduction
------------
 Extensions to the basic FITS format can be defined as specified in
Grosbol et al. (Astron. Astrophys. Suppl. 73, p359-364, 1988). The IAU
FITS Working Group (WG) under Commission 5 registers the names of such
conforming extensions. The status of a given extension can have one of
the following levels: 

   Status   Remarks
  ---------------------------------------------------------------
     S      Standard FITS extension accepted by the IAU FITS WG
            and recommended by the IAU.
     P      Proposal for FITS extension accepted by local FITS
            committees but not yet by the IAU FITS WG.
     D      Draft proposal to be discussed in local FITS commitees.
     R      Reserved FITS extension name for which a full draft proposal
            has not yet been submitted.
     L      Local FITS extension which has a limited scope only.

The table below gives a list of known names of FITS extension formats,
their status and reference organization:

      Ext-name   Status  Ref.   Remarks
   --------------------------------------------------------------------
     'TABLE   '    S     IAU    Defined in Astron. Astrophys. Suppl. 73,
                                p365-372, (1988).
    
     'BINTABLE'    D     IAU    Draft Proposal by W.Cotton and D.Tody
                                September 20, 1991.

     'IMAGE   '    D     IUE    Draft Proposal by J. D. Ponz, 
				R. W. Thompson, and J. R. Munoz;
				Feb. 7, 1992

     'COMPRESS'    R     GSFC   Suggested extension name (by A.Warnock);
                                Preliminary proposal.

     'FILEMARK'    R     NRAO   Suggested extension name (by D.Wells);
                                No full proposal submitted.

     'DUMP    '    R      -     Suggested extension name for binary dumps;
                                No full proposal submitted.

     'A3DTABLE'    L     NRAO   Extension used by AIPS and defined in
                                the 'Going AIPS' Manual Chapter 14.

     'IUEIMAGE'    L     IUE    Local extension defined for archiving
                                of special IUE data products.

Anyone who wants to register a FITS extension name should contact
either the NOST FITS Support Office
('bschlesinger@nssdca.gsfc.nasa.gov' or 'NSSDCA::BSCHLESINGER') or the
Chairman of the IAU FITS Working Group ('pgrosbol@eso.org' or
'ESO::PGROSBOL'). A short description and justification should be
submitted together with the request for registration.