You can find out whether a handle has already been taken by another person by logging in as guest (enter guest at the login prompt, you don't need a password to login as guest)and using the finger and handle commands. The command

verifies if the exact handle HandleExample has already been taken. If it is available, you'll see a message like

Remember to add the exclamation mark ! after the handle you wish to verify. You can also check the taken handles starting with a prefix. For example, the command

will list all taken handles (thus not available for new accounts) starting with "exa". A possible result of this command would be

   -- Matches: 12 player(s) --
   exa            exacto         examinee       exas
   exabyte        ExAddict       ExarKun        Exasparov
   Exachina       Exal           ExarkunKamikaz Exation
 

meaning that all handles starting with "exa" not in the above list are still available for new users.

Since the handle choice is forever (you are not allowed to change the handle after its creation, and you cannot create more than one personal account), we strongly recommend that you take some time to choose a handle you won't regret later. Handles that reflect transient characteristics such as current age, current school or the city you live are bad choices, since they will be wrong on your next birthday, after your graduation or after an address change. Handles that reflect religion or political opinions are also very likely to be regrettable. Examples of bad handles (avoid anything like these):