What could be documented: * Use cases for functional and declarative style * Common EXPORT_FUNCTION values for build system eclasses, unpacker eclasses etc. * Most common EAPI compatibility check snippet (one in devmanual is used nowhere) * "if [[ ! ${_ECLASS} ]]" snippet * How to debug eclasses References: https://blogs.gentoo.org/mgorny/2019/11/06/gentoo-eclass-design-pitfalls/