What are the basic rules for a good password?

Your password must be 6-8 characters containing:

• At least four characters must be different
• NEVER WRITE YOUR PASSWORD DOWN
• 3 of the following 4 character types:
• capitalized letter
• lower case letter
• number
• non-alphanumeric symbol

• What are the most crackable passwords?
• Why should I care about password security?
• How often should I change my password?
• I lost my password. What to do now?
• How do I protect my domain name record from unauthorized changes?