[PaulDavisThe1st]

30 years ago, I knew barely any more about library science than I do know, and I know basically nothing now. The idea was that of a dewy eyed (pun intentional) idealist who wanted to build an online experience similar to wandering into the gardening section at <your favorite large bookstore> and then dialing down the water garden part and then the japanese water garden part.

> the LOC Classification is a system for organising a printed (and largely bound) corpus on physical shelves/stacks. That is, any given document can occupy at most one and only one location, and two or more documents cannot occupy the same location,

The last part of this is not really true. The LoC classification does not identify a unique slot on any shelf, bin or other storage system. It identifies a zone or region of such a storage system where items with this classification could be placed. There can be as many books on Japanese water gardening as authors care to produce - this has no impact on the classification of those books. The only result of the numbers increasing is that some instances of a storage system that utilized this classification (e.g. some bookstores) would need to physically grow.

[dredmorbius]

The Classification doesn't establish unique positions, no, but it serves as the backbone on which those unique call numbers are generated. First the subject and sub-subject classifications, then specific identifiers generally based on title, author, and publication date.

But the detail of the Classification serves the needs and interests of librarians and readers in that you'll, for fairly obvious reasons, need more detail where there are more works, less where there are fewer, and of course changes to reality, as any good contributing editor to The Hitchiker's Guide to the Galaxy (the reference, not D. Adam's charming account loosely linked to it) can tell you, play havok with pre-ordained organisational schemes.

The LoC Classifiction itself is itself only one of these. There are other library classifications, as well as a number of interesting ontologies dating back to Aristotle and including both Bacons, Diderot, encyclopedists of various stripes, and more.