For those wondering about `rootless`, it is implemented as an extended attribute on files&#x2F;directories.<p>$ xattr &#x2F;usr<p>com.apple.FinderInfo<p>com.apple.rootless<p>Running `sudo rm -rf &#x2F;usr` fails.<p>$ sudo rm -rf &#x2F;usr<p>rm: &#x2F;usr: Operation not permitted<p>Here is a list of all of the `rootless` files and directories on my system. It appears to be mostly kext files, and Apple applications.<p><a href="https:&#x2F;&#x2F;gist.github.com&#x2F;bobbyburden&#x2F;4ce5c42044e5a9967b25" rel="nofollow">https:&#x2F;&#x2F;gist.github.com&#x2F;bobbyburden&#x2F;4ce5c42044e5a9967b25</a>