Password Policy defined in Dream Factory 2.0

I am using dream factory user management service for registering new users in my web site. While registering new users, when users enter number as passwords, dream factory returns 400: Bad Request error.
Can anyone tell me what password policies are supported by Dream Factory? (e.g. Minimum/Maximum Characters, Supported Characters etc.)

The only password policy built into DreamFactory is a minimum of 6 characters.