The most typical way of populating lists in forms is through the use of the allowedValues property. From this property, you can specify an optional list of permitted values for <Select> and <MultiSelect> elements. The value of this component is always a list and usually contains strings.
<Field name=’department’>
<Display class=’Select’ action=’true’>
<Property name=’title’ value=’Department’/>
<Property name=’allowedValues’>
<List>
<String>Accounting</String>
<String>Human Resources</String>
<String>Sales</String>
<String>Engineering</String>
</List>
</Property>
</Display>
</Field>