ansible/ansible — pull request #9802 by mscherer (2014-12-13 03:08:38+00:00)
Title: Document the behavior when a directory is used

For group_vars and host_vars, you can use a directory instead of a flat
file. This permit to have for example 1 private file coming from 1 git repo
containing per host variables, and 1 file coming from a public repository
( or less restricted internal repository ).