Note: This article is outdated. Previously, because pandoc doesn’t support non-ASCII identifiers, rmarkdown adds the +ascii_identifiers extension by default. As pandoc now supports it and rmarkdown no longer addes the extension, the issue gets resolved. Generally, the rmarkdown package supports non-ASCII strings very well, e.g., the link on the table of content works even for pure non-ASCII headers. However, I was bitten when using non-ASCII headers with the nice …