Your username and your domain Streamz usernames actually consist of two parts: The local username, e.g. alice And the domain of the website, e.g. streamz.ca Just like an e-mail address. For convenience sake, Streamz allows you to skip the second part when addressing people on the same server as you, but you have to keep in mind when sharing your username with other people, you need to include the domain or they won’t be able to find you as easily. I’m @alice on Mastodon! Wrong I’m @alice@streamz.ca on Mastodon! Correct I'm https://streamz.ca/@alice on Mastodon! Correct The search form in Streamz will find people either with the above address form, or the link to the person’s profile, so you can share that instead if you prefer. The same username can be registered on different servers – there is no way to claim all of them ahead of time. Just like with e-mail, you should not expect alice@outlook.com to be the same person as alice@gmail.com or alice@yahoo.com.