On this forum site, when you want to make sure that someone will read your post, you can mention their username with @ in front, like this:
This way, if they’re not reading the topic already, they will get a notification.
This @ mention system also works for groups of users, so for example if you place @ in front of beach_cleaners, all members of the ‘Beach Cleaners’ group will get notified.
This is useful when you want to invite someone to a conversation that they might be missing, or when you want a reply from someone specifically.
The person who started the topic gets notified by default, so it’s usually unnecessary to mention their name, and it will cause double posting.