I unfortunately did not study well enough to understand the paper. Can someone explain to me how this isn't some kind of Dewey Decimal Classification (https://

I unfortunately did not study well enough to understand the paper. Can someone explain to me how this isn't some kind of Dewey Decimal Classification (https://en.wikipedia.org/wiki/Dewey_Decimal_Classification https://en.wikipedia.org/wiki/Dewey_Decimal_Classification) ?