As @robwillmann has said, I sometimes link out to a site I am discussing and will add a tag or two that are relevant to the topic and the site. If I'm talking about a bitcoin-related site then I'd add tags such as "bitcoin", "crypto" and so on.
There's a useful post about using tags here:
https://hive.blog/hivewatchers/@hivewatchers/the-game-of-tags-updated-guide-2020