Since not all keyboards are the same, it is difficult to give style guidelines that are correct for every manufacturer's keyboard. To solve this problem, this guide describes keys that use a "Motif model keyboard" mechanism. Wherever keyboard input is specified, the keys are indicated by the engraving they have on the Motif model keyboard. The model keyboard does not correspond directly to any existing keyboard; rather, it assumes a keyboard with an ideal set of keys.
In addition to the standard letter, number, and character keys, the Motif model keyboard is composed of the following special keys:
The Motif model keyboard also contains the following optional keys, which, although useful, are either not necessary or may be created by combinations of other keys:
Throughout this guide, behavior is described in terms of model keyboard keys. When a behavior takes advantage of an optional key from the model keyboard, it is also described in terms of the required special keys. Each of the keys described on the Motif model keyboard must be available either as specified or by using other keys or key combinations if the specified key is unavailable. The following are a few of the more important alternative key bindings: