I've noticed a few times where people reference a #Bluesky account as simply "@ example" instead of (I assume) "@ example.bsky.social". Bluesky handles are domain names, so it's important to distinguish between, say, example.bsky.social and example.com.

Also, I again encourage anyone who's using Bluesky and has their own domain name/website to look into making it their handle instead of just relying on bsky.social.