Ubuntu Documentation > Ubuntu 9.04 > Ubuntu Server Guide > Security > User Management states that there is a default minimum password length for Ubuntu:

By default, Ubuntu requires a minimum password length of 4 characters

Is there a command for displaying the current password policies for a user (such as the chage command displays the password expiration information for a specific user)?

> sudo chage -l SomeUserName
Last password change                                : May 13, 2010
Password expires                                    : never
Password inactive                                   : never
Account expires                                     : never
Minimum number of days between password change      : 0
Maximum number of days between password change      : 99999
Number of days of warning before password expires   : 7

This is rather than examining various places that control the policy and interpreting them since this process could contain errors. A command that reports the composed policy would be used to check the policy setting steps.