the 'unprov' and 'finprov' folders - 

'unprov' contains unfinished and improvised odds and ends.
files make it to this location when they have certain qualities not assosiated with the idea of 'finished' pieces.
these files are available to be worked on by anyone under an adapted cc liscence.

'finprov' contains finished off pieces from the 'unprov' folder.
files make it to this location when they leave the 'unprov' folder due to becoming 'finished' pieces.
these files and all rights to the pieces have been donated to the therad.org archive.