[Leftium]

Histre is a site/browser extension that adds (AI-generated) tags to HN: https://hw.leftium.com/#/item/35904988

HN has a minimal tagging system based on the title:

- Ask HN: https://news.ycombinator.com/ask

- Show HN: https://news.ycombinator.com/show

- etc (some people create their own, like "Tell HN", "Thank HN")