The AT syntax is used to define the position of a gadget’s origin within a form. The position may be specified absolutely (in form layout grid units) or relative to the extremities of existing gadgets, or relative to the size of the form and the gadget.

The rest of the Forms and Menus syntax is described in Software Customisation Reference Manual: refer to that manual for more information, in particular about conventions used in the syntax graphs. The AT syntax graph is the easiest way of illustrating all the possible options, and so it is included here:

where <FGREL>, shown below, sets the gadget position relative to another gadget or the form’s extent. For example, it can be used to position a gadget half-way across the width of a form: