Difficult preposition "under"

[Duc]

Our new classification scheme lists books.... their title, not the subject.
In my book, it puts the preposition ''under'' but I don't understand.
Can you explain it for me?
I even don't understand the meaning of the sentence. It is so complicated, which is the main verb of the sentence?
_________________
Don't see your shade think you are great

[Jamie (K)]

The main verb of the sentence is "lists".

The reason we use "under" in that sentence is probably because when you visualize a list, you would imagine the book itself listed under the heading for the whole category. For example, if books were listed under their subjects, you would see something like this:

[Yankee]

[Duc]

Oh it's quite abstract.
_________________
Don't see your shade think you are great