It is a requirement when a visitor registers to comment or use the forum area that their callsign is used as their Username on the site. Non licencees use the the format swl followed by your country format and your name, all in lowercase, just like Twitter. This is clearly shown on the register page.
The reason is quite simple, it identifies who you are and from where you come. We have been receiving a large number of registrations which do not follow this format. Whilst I do not want to start deleting registered users, any incorrect format registrations received from 00:01UTC 8th Jan 2018 will be deleted and the user will have to re-register using the correct format.