# playbook-extension This rule checks the file extension for playbooks is either `.yml` or `.yaml`. Ansible playbooks are expressed in YAML format with minimal syntax. The [YAML syntax](https://docs.ansible.com/ansible/latest/reference_appendices/YAMLSyntax.html#yaml-syntax) reference provides additional detail. ## Problematic Code This rule is triggered if Ansible playbooks do not have a file extension or use an unsupported file extension such as `playbook.json` or `playbook.xml`. ## Correct Code Save Ansible playbooks as valid YAML with the `.yml` or `.yaml` file extension.