the default settings for the password strength are:
Minimum length: 6 characters
Maximum length: 500 Characters
Minimum letters: 3
Maximum letters: 500
Minimum Numbers: 3
Maximum Numbers: 500
The default spry error message is pretty clear about these requirements:
Password strength requirement not met. Your field must contain: a minimum of 6 and a maximum of 500 characters, a minimum of 3 and a maximum of 500 alphabet characters, and a minimum of 2 and a maximum of 500 numbers. 
This is set using a combination of Spry validation and Server Side Validation.
To double check or edit these settings, select the password field in design view, then click the blue bounding box around it. This will trigger the pry settings to show in the property inspector where you can see the minimum and max settings for characters, numbers and letters.
go to the server behaviors panel and double click the Server Validation server behavior. Inspect the entry length validation for the password field to see the settings for Minimum and maximum character count.
The is no PDF documentation for any of our extensions, but the built in help can be accessed through the help menu of dreamweaver or from the support page for the product through the built in help link:
securityassist/
