Here's a problem that AO3 users, like the rest of the internet, encounter every day: How do you find a particular thing you're interested in, while filtering out all the other stuff you don't care about?

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.

AO3's Tag Wrangling Chairs estimate that the group is on track to wrangle about 2.7 million never-before-used tags in 2019, up from 2.4 million in 2018.

One reason for the humans is that AO3 began developing its routines in 2007, when the tech wasn't as advanced and they had a lot of willing volunteers. But even now, tag wranglers are skeptical that a machine could take over their tasks.

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