DisplayPattern Element (List)
Used in computed fields to define how the field is rendered. The DisplayPattern section in the declaration for a computed field describes how the constituent fields are combined to form the computed field. For example, LinkTitle is a computed field type that combines Title and ID fields for a particular list item.
The built-in data types (such as Integer, Text, etc.) also have display patterns, which are defined in the FldTypes.xml file. The Field element can contain display patterns and, for this reason, can be used to apply rich formatting to values (unlike the Column element, which simply returns raw data).
The following example creates a computed field called LinkField that combines values of the Title and ID fields to form links such as <a href="form.htm?ID=7">This is the title</a>.
<Field Name="LinkField" Type="Computed"> <FieldRefs> <FieldRef Name="Title"/> <FieldRef Name="ID"/> <FieldRefs> <DisplayPattern> <HTML><![CDATA[<a href="form.htm?ID="]]></HTML> <Column Name="ID"/> <HTML><![CDATA[">]]></HTML> <Column Name="Title"/> <HTML><![CDATA[</a>]]></HTML> </DisplayPattern> </Field>