http://www.kinook.com/UltraRecall/Ma...plategroup.htm
Each Core Template and all the Templates derived from it constitute a Template Group. Any Info Item can switch to any other Template in the same Template Group.
Core templates:
http://www.kinook.com/UltraRecall/Ma...etemplates.htm
e.g. you cannot change pdf document to text item, because one is based on "Document" core template and other on "Text" core template.