It's useful. I looked at it last night for a refresher. Also, look at other major distros. And, for building packages and patches, look at LFS, Free/Open/NetB

It's useful. I looked at it last night for a refresher. Also, look at other major distros. And, for building packages and patches, look at LFS, Free/Open/NetBSD ports, homebrew, macports, linuxbrew, habitat, NixOS, Debian, Ubuntu, Fedora, OpenSUSE and Arch. For security advisories, be sure to check the multitude of sources... note that more than few released packages ship vulns that need patching and some packages are essentially abandonded. Have a look at the old RHEL 5 NSA hardening guide and other major guides for Linux hardening too (be sure to compile things using modern toolchain hardening flags, and test them thoroughly and relentlessly to suss out gotchas). The big things with distros is package updates and system upgrade securely delivered (Debian flavors are good at this), don't break a system and don't interrupt users unexpectedly. Most distros' packaging systems are flexible but confusing and under-documented packaging descriptions. Habitat and Arch are cleaner.