There is a Player Name and Player Short Name.

There is a Disc name and Disc number.

There is a graphical option that will display disc numbers on buttons and as part of doing this, uses the Player Short Name prepended to the Disc Number.

So, assuming 4 players A, B, C, D, you would have disc numbers A001 - A400, B001-B400, etc....

With regard to sorting by disc number, I don't believe that this is an option and I have no plans or desires to add such capability as SNL is primarily useful for Classic Prontos and via Importing, Pronto NG remotes natively in the CCF format.