Administering : Managing business rules and expressions : Using expressions as values
  
Using expressions as values
You can set an expression to be the default value of an attribute for an element.
To use an expression as the default value of an attribute
1 Click the Settings icon Settings icon, and then, from the Configure group, click Attributes.
2 Select a module.
3 Select an existing attribute by clicking its link, or add an attribute by clicking Add Attribute.
4 In the Default value field, type:
=
The Evaluate Expression, Help, List Business Rules options are displayed.
5 To evaluate the expression before you save it, click Evaluate Expression.
6 Click OK.
Note The attribute value of all new elements will be an expression. You can edit the expressions in the attributes lists of the element. You can also enter a new expression, and enter a “normal” attribute value.
See
Managing business rules and expressions