##### 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.

cmd = [self.module.get_bin_path('usermod', True)]
        cmd_len = len(cmd)
        info = self.user_info()
        if self.uid is not None and info[2] != int(self.uid):
            cmd.append('-u')
            cmd.append(self.uid)
            if self.non_unique:
                cmd.append('-o')
        if self.group is not None:
            if not self.group_exists(self.group):
                self.module.fail_json(msg="Group %s does not exist" % self.group)
            ginfo = self.group_info(self.group)
            if info[3] != ginfo[2]:
                cmd.append('-g')
                cmd.append(self.group)
        if self.groups is not None:
            current_groups = self.user_group_membership()
            groups = self.get_groups_set()
            group_diff = set(current_groups).symmetric_difference(groups)
            groups_need_mod = False