saltstack-formulas/users-formula — pull request #58 by TimJones (2014-12-17 22:03:02+00:00)
Title: Allow '!' prefix in password for disabled\locked accounts.

Without single\double quotes around the user password, PyYAML interprets the ! as a tag variable, rather than the first character of the password string.

This means passwords cannot be set to '!' (to disable log in) or '!$6$....' (to lock accounts).