Pkg_cutleaves looks at installed packages and notifies the user of packages upon which no other package depends. These “leaf packages” might be candidates for removal. When done with the first round of deletions, pkg checks again to see if any of the deletions created new leaf packages. If so, the user is asked to keep or deinstall each leaf package. When totally done, the tool informs the user. of all packages it deleted. When done, it tells the user what packages it deletes.”]
Source: https://taosecurity.blogspot.com/2004/03/removing-packages-with-pkgcutleaves.html