Users tend to base their passwords on regular words of the spoken language, and crackers know that. <application>CrackLib</application> is intended to filter out such bad passwords at the source using a dictionary created from word lists. To accomplish this, the word list(s) for use with <application>CrackLib</application> must be an exhaustive list of words and word-based keystroke combinations likely to be chosen by users of the system as (guessable) passwords.