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##### SUMMARY
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https://docs.ansible.com/ansible/latest/collections/ansible/builtin/password_lookup.html :

> Define comma separated list of names that compose a custom character set in the generated passwords.
> They can be either parts of Python's string module attributes (ascii_letters,digits, etc) or are used literally ( :, -).

I suggest to list all possible names or at least add a link to python string module documentation: https://docs.python.org/3/library/string.html

Now you have to search for the relevant python documentation yourself.

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##### ISSUE TYPE
- Documentation Report

##### COMPONENT NAME
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ansible.builtin.password

##### ADDITIONAL INFORMATION
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from __future__ import (absolute_import, division, print_function)
__metaclass__ = type
DOCUMENTATION = """
    name: password
    version_added: "1.1"
    author:
      - Daniel Hokka Zakrisson (!UNKNOWN) <daniel@hozac.com>
      - Javier Candeira (!UNKNOWN) <javier@candeira.com>
      - Maykel Moya (!UNKNOWN) <mmoya@speedyrails.com>
    short_description: retrieve or generate a random password, stored in a file
    description:
      - Generates a random plaintext password and stores it in a file at a given filepath.
      - If the file exists previously, it will retrieve its contents, behaving just like with_file.
      - 'Usage of variables like C("{{ inventory_hostname }}") in the filepath can be used to set up random passwords per host,