1.2 Scope

This standard specifies the organization and content of FITS data sets, including the header and data, for all  standard FITS formats: Basic FITS, the  random groups  structure, the ASCII table  extension, the image  extension, and the binary table  extension. It also specifies minimum structural requirements for new extensions  and general principles governing the creation of new extensions. It specifies the relation between physical block sizes  and logical records for FITS files on bitstream devices and sequential media. For headers, it specifies the proper syntax for card images and defines required  and reserved  keywords. For data, it specifies character and value representations and the ordering of contents within the byte stream. It defines the general rules to which new extensions are required to conform.