The Query Reference Manual describes the Query command syntax which you can use to set up links between Plant and an external database. It is intended for those who need to write application macros for use from within those products, the principal purpose of such macros being to allow users to interrogate a database and to use the results to control Plant operations in a user-friendly manner. The manual does not attempt to define rules for writing such macros, nor does it tell you how you should document the ways in which end-users should use your macros and their controlling interfaces.