##### SUMMARY
The documentation of the module *user* / parameter *shell* states:

https://github.com/ansible/ansible/blob/8edad83ae029d7838a6d6347576d2ddbcce12ad0/lib/ansible/modules/system/user.py#L79

But there are no (shell specific) notes.
##### ISSUE TYPE
- Documentation Report

##### COMPONENT NAME
user / docs

##### ANSIBLE VERSION
devel branch

##### CONFIGURATION
N/A

##### OS / ENVIRONMENT
N/A

##### ADDITIONAL INFORMATION
Either remove the sentence or provide some information in the notes section.

if len(fields) >= 3:
                        
                        if bool(_HASH_RE.search(fields[-1])):
                            maybe_invalid = True
                        
                        if fields[1] == '1' and len(fields[-1]) != 22:
                            maybe_invalid = True
                        
                        if fields[1] == '5' and len(fields[-1]) != 43:
                            maybe_invalid = True
                        
                        if fields[1] == '6' and len(fields[-1]) != 86:
                            maybe_invalid = True
                    else:
                        maybe_invalid = True
            if maybe_invalid:
                self.module.warn("The input password appears not to have been hashed. "
                                 "The 'password' argument must be encrypted for this module to work properly.")
    def execute_command(self, cmd, use_unsafe_shell=False, data=None, obey_checkmode=True):
        if self.module.check_mode and obey_checkmode:
            self.module.debug('In check mode, would have run: "%s"' % cmd)
            return (0, '', '')
        else:
            
            cmd = [str(x) for x in cmd]
            return self.module.run_command(cmd, use_unsafe_shell=use_unsafe_shell, data=data)
    def backup_shadow(self):
        if not self.module.check_mode and self.SHADOWFILE:
            return self.module.backup_local(self.SHADOWFILE)
    def remove_user_userdel(self):