Once you have created and saved a couple of XML Template files you will notice that when you retrieve from host a screen that already has a XML Template that matchs, it is automatically selected and shown in the display. When a screen arrives, the XML Template engine looks in the template's directory for the template that own those XML Template Fields that have the "Identity" attribute set to true and match in the current screen.

When generating XML Template Fields in automatic way, these fields are in general determined by Development Lab. However as we said, this is far beyond perfect, so you might need to modify this attribute on some fields.

Always take into account that "Identity" fields must be those that are unique to the screen and wont suffer any change neither in its content nor its location.