YAML Norway Problem Persists in 2026: NO Country Code Parsed as False
Original: YAML? That's Norway problem
Why This Matters
Highlights ongoing compatibility issues in widely-used data serialization standards affecting developers worldwide.
A technical analysis reveals YAML's ongoing Norway problem where the country code 'NO' gets incorrectly parsed as false boolean instead of string. Despite YAML v1.2 specification changes, popular libraries like PyYAML 6.0.3 still exhibit this behavior in 2026.
The article demonstrates YAML's notorious 'Norway problem' where the country code 'NO' is automatically converted to boolean false during parsing. Testing with Python's PyYAML 6.0.3 library shows that adding 'NO' to a list of country codes results in false appearing in the parsed JSON output. This occurs because YAML was designed to parse words like 'no', 'yes', 'true', and 'false' as booleans for human readability in configuration files. The workaround involves quoting the string as '"NO"' to force string parsing. The problem traces back to YAML's original design philosophy of making configuration files read like natural language, but has proven problematic in practice for data containing these boolean-like strings.