A catalogue in DIRA2 is an ASCII file, written in a table format, that contains one record for each astronomical object (.DAT files). The physical description of catalogues and catalogue variables are written in the DIRA2 system files (.DB files) and are used in a transparent way by the DIRA2 commands. The users can investigate on these data to search for particular classes of catalogues in the data base with the DB_INFO command. At the PDB level, the users can manage these files using the PDB_MANAG command.
Moreover each catalogue has a related file (.DOC) that contains the documentation in a printable format. We have added to the available astronomical documentation some entries of informational use: number of records, code and format of the variables contained in each record, full explanation of adopted code etc. At the Personal Data Base level the user can create documentation files for self-created catalogues.