ever wanted that one nickname only to discover that some three years old 0 battle account has it? You're in luck: Wargaming started a program to rename such old inactive accounts to "technical" names, releasing the good ones for public use, as confirmed by LJ user Evilsexybear.
How it works: the owner of an inactive account receives an e-mail notification to log in within 10 days. If he does not do that, the account will be renamed to a "technical" temporary name and the nickname it had will be released to public.
This is how the letter looks in Russian. It is not known whether this program is active for EU and NA servers but on RU, it is (the name of the account was shopped away of course).