The ASTRO catalog format is one of the two following ones: A comma separated value file, including the frequency in MHz, the species name, and the transition name, e.g.: 150E3; MOLE; TRANSITION; A list-directed file, with the same information, e.g.: 150E3 'MOLE' 'TRANSITION' Lines beginning with an exclamation mark are considered as comments. The first line **MUST** be a comment line. A default catalog (with no implied warranty) is given in gag_data:mole- cules.dat.