# Parts You can add parts to organize one or more book chapters together. Parts can be inserted at the top of an .Rmd file, before the first-level chapter heading in that same file. Add a numbered part: `# (PART) Act one {-}` (followed by `# A chapter`) Add an unnumbered part: `# (PART\*) Act one {-}` (followed by `# A chapter`) Add an appendix as a special kind of un-numbered part: `# (APPENDIX) Other stuff {-}` (followed by `# A chapter`). Chapters in an appendix are prepended with letters instead of numbers.