The native format in which GAIA reads and writes the catalogues and tables which it plots as image overlays is the so-called Tab-Separated Table (TST) format, which is described in SSN/75. GAIA can also read and write catalogues in the FITS tables, STL and ASCII_HEAD formats. GAIA differentiates between these different formats by using the file-type at the end of the file-name. Brief notes on the individual formats and their required file-types follow.
Mixed capitalisations, such as `.Fits' are also recognised. GAIA interprets all other file formats as indicating TST format catalogues (but note that CURSA requires TST format catalogues to have a file-type of .TAB or .tab).
The GAIA Cookbook