The settings tab lets you make adjustments to your rom and artwork names to help with matching. If you have a rom named 123Tempest.rom, and trim 3 characters from the left, when the program starts matching it will use Tempest.rom as the name to use as the match name for the rom.
The other side for the Artwork works the same way:
If you have an art file named Tempest123.jpg and trim 3 characters from the right, when the program starts matching it will use Tempest.jpg as the name to use for the match name for the Artwork.
When you switch to the match tab, and start matching, Tempest123 with be shown as the suggested artwork for the rom Tempest123, with a 99% probability of a match since with the settings that you have chosen, they are seen by the match program as an exact match. If the two file names had actually been an exact match (without applying the settings that you chose) they would have been shown as a 100% match.
Given the example above, the match tab would display
RomName | Suggested ArtWork | Match%
123Tempest | Tempest123 | 99.9%
When you select that row to rename, The ARTWORK would be renamed to 123Tempest. Perfect Match NEVER alters the rom names themselves.
You can use the project menu to save a project that you are working on. When you run Perfect Match again, that project will reopen, and everything should be as you left off, including all of the settings, and the Match Tab.
You do not have to save a project. Perfect Match will create a default project when first run, and that is the project that will be used unless you save the default project as something else. Perfect Match ALWAYS save your settings for the current project on exit, whether it be the default project, or a project that you have saved. The current project name is shown in the bottom left corner of the GUI as shown in the screenshots as 'Default'
I should also mention that you can work with more than one artwork folder at a time. Use the 'add' button to add a second (or third etc...) path. The path that is shown in the box is the 'Primary' path. Artwork in the secondary paths are also renamed at the same time, as long as the names in the primary and secondary folders match EXACLY. In other words, you should be able to rename your boxes, carts, screenshots, etc all at the same time.