Is it possible to re-use the username of a permanently disabled account?

Environment:

Creating usernames in Staff Accounts
Oracle B2C Service, all currently supported versions

Resolution:

Usernames must be unique.  Once a username is assigned to an account, it can not be used again even if the previous account is permanently disabled. The reason for this is that we have identified issues caused by re-using permanently disabled usernames. No re-using usernames prevents those issues.

For information on disabling an account, refer to Answer ID 570: Disabling a staff account.