Norway's 2 character country code abbreviation is "NO". Which is one of the many ways to spell the boolean `false` in YAML 1.0. Which is yet-another-way-to-shoot-yourself-in-the-foot with DSLs written in YAML.

Likely a joke with the YAML parsers that parse `NO` as the boolean value `false` when the writer of the YAML file intended to put Norway's 2-character code as a key in a map.