Fan fiction writers are better than tech at organizing information online

This deep-dive into AO3's tagging system is pretty interesting. The idea of using "tag wranglers" to pair up synonymous tags so you can still find what you're looking for is pretty novel.

On AO3, users can put in whatever tags they want. (Autocomplete is there to help, but they don't have to use it.) Then behind the scenes, human volunteers look up any new tags that no one else has used before and match them with any applicable existing tags, a process known as tag wrangling. Wrangling means that you don't need to know whether the most popular tag for your new fanfic featuring Sherlock Holmes and John Watson is Johnlock or Sherwatson or John/Sherlock or Sherlock/John or Holmes/Watson or anything else. And you definitely don't need to tag your fic with all of them just in case. Instead, you pick whichever one you like, the tag wranglers do their work behind the scenes, and readers looking for any of these synonyms will still be able to find you.

AO3's trick is that it involves humans by design—around 350 volunteer tag wranglers in 2019, up from 160 people in 2012—who each spend a few hours a week deciding whether new tags should be treated as synonyms or subsets of existing tags, or simply left alone. AO3's Tag Wrangling Chairs estimate that the group is on track to wrangle over 2 million never-before-used tags in 2019, up from around 1.5 million in 2018.