So that's it. Thanks for answers

Aleutia must be a deactivated character, rather than a deleted one. Deactivated characters won't show up when you search for them.

I didn't mean characters that exist on the site from users with deleted accounts. I meant DELETED characters, whose name data still exist on the site.
For example type "Aleutia" in seach. There's no such character with this name(I mean just Aleutia. no dots, no usernames), but looks like there was, because I couldn't name my character "Aleutia".

If you want to use a character name, you can PM one of us to delete the character. I'm not sure if this still applies but members before couldn't change a character name so if you have a character and you want the name to be changed to an existing character;s name, with a deleted account, we can again delete that character then change the name for your character.
I've done that several times before. So it might work.

You're welcome to PM us if you find a character with a deleted account owner.

When a user deletes their account, their content remains on the site. So clearing the site cache is not going to solve the problem. There are two answers on how to solve this. Report the problem character to the mods stating that the user no longer exists and that you want to use that name. The second option would be to add your username to the name of the character.