YAML Ain't Markup LanguageFAQ Is there an official extension for YAML files? Please use ".yaml" when possible. Why does YAML forbid tabs? Tabs have been outlawed since they are treated differently by different editors and tools. And since indentation is so critical to proper interpretation of YAML, this issue is just too tricky to even attempt. Indeed Guido van Rossum of Python has acknowledged that allowing TABs in Python
