Chapters

• Fix “Invalid Escape Sequence Near \%” in LuaLaTeX Chapter Titles
  Lua rejects the backslash-percent escape in a string literal. Use character codes to emit TeX’s percent command, and protect the macro in chapter titles.
• How to Center Selected Chapter Headings in LaTeX
  Use sectsty's \chapterfont locally to center selected chapter headings while leaving other chapters unchanged, with a complete book-class example.