item properties #archive:f:\... - what does it mean?

I have mostly ISOs in my Video library. I added them with Scan Drive/Folder For Media Files...

What does the "#archive:" prepended to the Location value mean?

For example, movie X when brought into the Library, gets three objects X (Title 1), X (Title 2), X (Title 3). Only X (Title 3) plays through Mezzmo to my TV or XBMC. On Titles 1 and 2 - Location is prepended with #archive.

What is #archive? If its entry is non-playable why is the Title even generated?

Can I just get rid of the non-playable Title 1 and 2? Will they come back with future "Maintain" activities?

The "#archive" is a special keyword that tells Mezzmo the file is a gapless multi-file (i.e. a file that is made up of parts of many files). DVD videos can be multi-files and gapless music can be multi-files. You can ignore the "#archive" location path and, instead, right-click on the video and click Properties. In the Properties dialog, go to the Gapless Multi-file tab and you will see the video files listed that make up the multi-file, including offsets.

When Mezzmo analyses a DVD fileset or DVD ISO, it finds all the videos from the menu and creates a separate video in Mezzmo such as "Movie (Title 1)", "Movie (Title 2)", etc.

You may not want some of these videos (e.g. they are outtakes, trailers, etc.). You can remove the videos that you do not want in Mezzmo.