Now that you're a more knowledgeable person, I hope you can add new items to a list or keep your key-value pairs aligned without any trouble. You can freely create or adjust your YAML files to your taste by swapping to/from the alternative formats, changing the order of the keys in a map and adding/removing comments.
There is other data serialization format, and each of him has pros and cons.
- XML was excellent, and XHTML his born from him
- MessagePack have the best performances, but isn't human readable