Nice suggestion. Seems like RAL is equivalent to Pantone but in Europe. I’ll look into its licensing and implement it if it’s not much of a headache :)
RAL is often used in manufacturing. Our powder coater used RAL colors for example.
RAL and HKS are German color systems, the first dating back to the 1920s and the latter to the 1960s.
Edit: love the app!
RAL is often use for paint. E.g. if you want to paint your building in Pantone you normally get it converted.