I noticed while poking around today that many interesting categories for an article are not always applied to the article page, but to the talk page. For example: https://en.wikipedia.org/wiki/Talk:Agaricus_deserticola
This has the categories:
- Wikipedia featured articles
- Featured articles that have appeared on the main page
- Featured articles that have appeared on the main page once
- FA-Class Fungi articles
- Mid-importance Fungi articles
- WikiProject Fungi articles
If we were doing one-hot encoding of "important" categories, it seems it would be usefull to have things like featured articles as on of those values.