It would be interesting/fun to hear how your naming system with regards to discs have changed.
If there are 'artistic' reasons why there are references to disc numbers, I will use them.
E.g. for a James brown box-set, I have:
Disc 1: Mr. Dynamite
Disc 2: The Hardest Working Man in Show Business
Disc 3: Soul Brother No. 1
Disc 4: The Godfather of Soul
But if the only reason for disc numbers is the limitation of 74 mins of playing time of a cd, s***w it.
E.g. there are 'deluxe' re-releases that may have two disks.
disc 1 has the 8 songs from the original album, plus 3 bonus tracks.
disc 2 has 10 bonus tracks.
Using, and depending on disc numbers here would only confuse me, so I will use set-subtitles instead, defining and separating the original tracks from the added re-release tracks.
This does conflict with the strict librarian in me, but I like to let the pragmatic music-lover win once in a while.