# Meaning of Variable Name Starting With "\_\_"?

**URL:** <https://forum.ansible.com/t/meaning-of-variable-name-starting-with/26239>\
**Category:** Ansible Project\
**Created:** [December 9, 2017, 10:09pm UTC](https://forum.ansible.com/t/meaning-of-variable-name-starting-with/26239 "2017-12-09T22:09:31Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Robert\_F](https://avatars.discourse-cdn.com/v4/letter/r/9d8465/32.png) [@Robert\_F](https://forum.ansible.com/u/Robert_F)\
**Post date:** [December 9, 2017, 10:09pm UTC](https://forum.ansible.com/t/meaning-of-variable-name-starting-with/26239/1 "2017-12-09T22:09:31Z")

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I’m about to use geerlingguy.apache and saw this code in the main.yml task:

`

- name: Define apache\_packages.  
set\_fact:  
apache\_packages: “{{ \_\_apache\_packages | list }}”  
when: apache\_packages is not defined  
`

What does this double underscore mean? \_\_apache\_packages

I know that double underscores usually indicate a private variable in some languages. Is that the meaning in Ansible/YAML?

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<div class="post-metadata">

**Author:** ![Kai\_Stian\_Olstad](https://avatars.discourse-cdn.com/v4/letter/k/e19adc/32.png) [@Kai\_Stian\_Olstad](https://forum.ansible.com/u/Kai_Stian_Olstad)\
**Post date:** [December 10, 2017, 12:06am UTC](https://forum.ansible.com/t/meaning-of-variable-name-starting-with/26239/2 "2017-12-10T00:06:15Z")

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> I'm about to use geerlingguy.apache and saw this code in the main.yml task:
> 
> - name: Define apache\_packages.  
> &nbsp;&nbsp;set\_fact:  
> &nbsp;&nbsp;&nbsp;&nbsp;apache\_packages: "{{ \_\_apache\_packages | list }}"  
> &nbsp;&nbsp;when: apache\_packages is not defined
> 
> What does this double underscore mean? \_\_apache\_packages

For Ansible nothing other than that underscore is just a valid character for a variable.

> I know that double underscores usually indicate a private variable in some  
> languages. Is that the meaning in Ansible/YAML?

You would need to ask the author of the role.