RESOLUTION C1: Flexible Image Transport System Commission 5 considering the present unsatisfactory situation of the transfer of astronomical data between astronomical institutions recommends that all astronomical computer facilities recognize and support the Flexible Image Transport System (FITS) for the interchange of binary data on magnetic tape, as described in Astronomy and Astrophysics Suppliement, vol. 44, pp. 363 and 371This resolution was then adopted by the IAU General Assembly in an omnibus resolution (R11) which endorsed all 16 of the various commission resolutions from that General Assembly meeting.
This resolution refers to the first 2 published papers about FITS: Paper I by Wells et al. provides the basic definition of the FITS format. Paper II by Greisen and Harten defines an extension to the basic FITS format for Random Groups.
Reference: Transactions of the International Astronomical Union (1982), Vol. XVIIIB, pp 45-46.