The form body contains Field elements that define how each element of the Web page appears and behaves. Each Field can contain other fields, each with its own display component.
Form fields comprise several parts, which are encapsulated by the <Field> tag set:
Value Expressions. The field can contain a number of XPRESS expressions, which calculate the value of the field or define the set of allowed values. For example, <Default> is used to define the default value of a field, and <Derivation> is used to derive the value for the field when the form is first loaded. Not all field elements contain expressions. See the section titled Field Display Properties.
HTML Display Components. Display components determine how visible elements are displayed. In Identity Manager form fields, display components (defined in the form by the <Display> element) determine the behavior and appearance of form fields. You can specify only one display component for each field. These display components are described in detail in Chapter 7, HTML Display Components
Disable Expressions. Fields can be conditionally included in the form by using Disable expressions. If the Disable expression evaluates to true, the field is ignored.