This repository is a comprehensive, community-maintained cheat sheet for favicon sizes, types, and best practices. It covers everything from minimal modern setups (SVG favicons with dark mode support, 180x180 apple-touch-icon, manifest.json) to exhaustive legacy browser support across iOS, Android, Windows, and older browsers. The README includes detailed HTML markup, image creation instructions, ICO file specifications, helpful tools, and a FAQ. The only other file is a PDF (FaviconGuides.ai), an Adobe Illustrator vector graphic that visually documents favicon sizes. There is no executable code or software; the repo is purely a static reference document. Its quality lies in the depth, accuracy, and practical utility of the information, which is regularly updated to reflect modern standards.