The Dewey Decimal Classification
What about the Dewey Decimal Classification (DDC), the system that most people in a public library are used to, rather than the significantly more academically-inclined LC system? The Dewey Decimal Classification is under copyright to OCLC (Onlince Computer Library Center), and they will happily tell you that it always has been. If you want to know how the Dewey Classification works and to be able to use it correctly, you're going to have to pay for it. In a subscription. Worse, the DDC has been with us for about 150 years and has put out 23 releases, which officially makes its update schedule slower than Debian Linux. We're paying for a system that doesn't respond quickly to new things, and doesn't reconfigure itself when serious problems are pointed out with its structure. For example, ranges 200-290 in the DDC are almost exclusively devoted to Christianity, leaving a tenth of the possible ranges available for other religious belief systems. Computers and technology weren't around when the DDC first came into existence, so they have all been shoehorned into the 000 range, under "General Knowledge".