Saving a project as a disk image initally has saved me many coasters over the years. A last opportunity to catch little things often missed during editing like spelling errors, overly loud audio etc. Generally, that word image means in a standard .iso format filetype, but it's usual to at least once confirm that detail in a user guide.

In the PD18 user guide, the index at the back has an entry (p518) for ISO image 468,470. However, on those pages there is no mention of an iso filetype, simply several references to
· Save as disc image: select this option if you want to create a disc image file on
your computer's hard drive. Disc images can be burned to disc at a later time
if required. Click on to specify the folder where it is created.

But there is no mention in those indexed pages of the filetype that is used, nor how the image can be burned at a later time.

Confirm that the image saved with this option is a standard .iso filetype?
Advise whether PD18 can import that disk image and burn it, or whether an external program is needed to do that?