Following the source of Cracklib 2.7 possible return strings are:
- it is based on a dictionary word
- it is based on a (reversed) dictionary word
- it's WAY too short
- it is too short
- it does not contain enough DIFFERENT characters
- it is all whitespace
- it is too simplistic/systematic
- it looks like a National Insurance number
It may be useful for example in localization of your scripts...