But that's an legal thing in Germany, not a convention. Also, because it's a codified law, you're perfectly allowed to use Nazi symbology in many contexts where US people would still feel they have to use the "n-word". The rules are a bit similar to "fair use" in copyright.
Splitting hairs. Laws arise from conventions. And people still use the n word in many non-racist contexts here. The first amendment blocks the codification if this in law but the principle is the same: shun the words and symbols that these systems of oppression were built on.
