To source an inventory from a project and define an inventory source, only .ini-formatted inventory files within the project will appear in the Inventory File dropdown. While .yml-formatted inventory files are supported, they must be added manually by typing in the path and filename, as they do not appear as selectable options in the dropdown.
 
Also, when defining inventories as .yml files, they may appear in the Playbook selection dropdown within Job Templates, even though they are not valid playbooks. This can lead to confusion and frustration for customers, as these inventory files are incorrectly listed alongside actual playbooks.