>>11782208By the number you assign them in your personal catalogue. Works for everything: textbooks, saved webpages, music, porn, gifs.
You have to create a catalogue of course, and each entry needs a rich text file containing all of the associated metadata for that entry, so that if you browse all of your files in alphabetical order it looks like this:
[catalogue name]00027372.gif
[catalogue name]00027373meta.pdf
[catalogue name]00027274.epub
[catalogue name]00027274meta.pdf
And so on. If you want to implement tag search functionality without having too much coding work just create a bunch of lookup tables and manually edit them every time you add something to the catalogue.