Figure: Display Object Structure
The top level structure of a display form object is summarized by the
grammar shown in Figure 
. An object contains
one or more display form definitions. Each definition has a
term which the display form applies to, and a sequence of formats
that specify how to display the term. A definition also has an
optional sequence of attributes that specify extra information about
the definition. Usually, all the definitions in one object refer
to a closely related set of terms. When choosing a display form to
use for a term, the layout algorithm tries definitions in a backward order,
so definitions are usually ordered more general to more specific.