1 Introduction

If an application prompts the user for a catalogue (or table) using the facilities of the CAT_ system (see SUN/181), the user may only reply with the name of a single catalogue. Some applications allow many input catalogues to be specified and the need to type in every catalogue name explicitly each time the program is run can become time consuming. The CTG package provides a means of giving the user the ability to specify a list (or Group) of catalogues as a reply to a single prompt for a parameter.