# Yaml merge keys This crate implements support for the [Merge Key Language-Independent Type for YAML][] draft specification for YAML documents from the `yaml-rust` and `serde_yaml` (with the `serde_yaml` feature) crates. When a mapping in a YAML document contains a `<<` key, its value should be either a mapping or a sequence of mappings. For each mapping, it is merged into the parent mapping where the parent mapping wins conflicts (so that it may override keys from the merge set). [Merge Key Language-Independent Type for YAML]: http://yaml.org/type/merge.html