About a year ago I had such trouble with our national organisation for handling economical rights to our music. When I was about to register the sixth out of twelve pieces included in my "Tolv tvåstämmiga stycken för solo piano" (Twelve two-part pieces for piano solo) and was about to write the title and "...from Twelve two-part pieces for piano solo" and the space once again was not big enough I decided to try a different method.
I chose the opus numbering system. Then I could easily write the title of the piece and then just add op. X no. Y to it.
Ironically these pieces didn't get a number since I got picky, when I got to assign the numbers to my compositions.
This left me with two groups of pieces; numbered and unnumbered which has led me into a greater freedom when I compose since most pieces do not get an opus number and only those that I am really pleased with do. They are the face that I show to the world.
Have you done something similar? Given your compositions opus numbers, or grouped them into larger "works", or cataloged them in some other way for some reason.
It would be interesting to hear your thoughts about this.