When saving an image as a Template, any existing guidelines should be saved to 
the template file.  When loading a Template, or creating an image from a 
Template, the saved guidelines should be recreated.

Here's a nice real-world example.  Many companies offer image-to-business-card 
services, with "full bleed" printing.  They tell you to provide an image that 
exceeds the final product area by a given amount.  A Template for business 
cards could offer the full image area, with guidelines for the final image area 
after the printer crops to the appropriate size.