yaml file extension

This is totally cosmetic, but thought I'd ask...

In the past I've usually seen the extension .yaml, but all the examples and tests in ansible use ".yml". Funnily enough there is one .yaml file, the YAML documentation. I've looked it up and found:

http://www.yaml.org/faq.html
Is there an official extension for YAML files?
   Please use ".yaml" when possible.

Any reason for having picked .yml?

Three letter extensions owe historical relevance from DOS.

They also save typing.

I'm really not interested in changing them, but if you name them
".gizmo_widget" everything will still work. There is nothing in
Ansible that cares about file extensions.

Yes I noticed, I went with .yaml for my playbooks, and it's fine.

mine use the extentions .no_its_not_xml_so_it_is_actually_human_readable