does bitcointalk previously allow to post without any account? or what is this type of username ("anonymous, guest") with reply?
Years ago, Bitcointalk allowed users to delete their accounts, change usernames but it did not last long.
Later only Bitcointalk admins, staffs, VIP members and Donators can change their usernames by themselves. Other members will have to open requests to admins and wait for approvals.
As you can see here, I only change the username to "Anonymous" on request.
It's not possible. Just abandon it.
Done. Now only moderators, Donators, and VIP members can change their names automatically. Other members should contact me. I'll probably ignore your request if you have less than 50 posts (unless your posts are very good).
In the last three years, theymos has been more friendly to change usernames for cases if he sees fit.