Are you sure? I’ve always heard it the other way around and a quick search for "YAML norway’ gives this

The reason to why this is problematic in some cases, is “The Norway Problem” YAML has: when you abbreviate Norway to its ISO 3166-1 ALPHA-2 form NO, YAML will return false when parsing it

Also, YAML 1.2 (2009) changed the format of booleans to only be case insensitive true and false. “No” no longer is false if you’re parsing as a version 1.2 document.