/etc/portage/make.profile/ or /etc/make.profile/
              site-specific overrides go in /etc/portage/profile/
              deprecated
              eapi
              make.defaults
              packages
              packages.build
              package.accept_keywords
              package.bashrc
              package.keywords
              package.mask
              package.provided
              package.unmask
              package.use
              package.use.force
              package.use.mask
              package.use.stable.force
              package.use.stable.mask
              parent
              profile.bashrc
              soname.provided
              use.force
              use.mask
              use.stable.mask
              use.stable.force
              virtuals

       /etc/portage/
              bashrc
              categories
              color.map
              license_groups
              make.conf(5)
              mirrors
              modules
              package.accept_keywords
              package.accept_restrict
              package.env
              package.keywords
              package.license
              package.mask
              package.properties
              package.unmask
              package.use
              postsync.d
              repo.postsync.d
              repos.conf
              sets.conf

       /etc/portage/env/
              package-specific bashrc files

       /etc/portage/profile/
              site-specific overrides of /etc/portage/make.profile/

       /etc/portage/sets/
              user-defined package sets

       /var/db/repos/gentoo/
              sets.conf

       /var/db/repos/gentoo/metadata/
              layout.conf
              pkg_desc_index

       /var/db/repos/gentoo/profiles/
              arch.list
              categories
              info_pkgs
              info_vars
              license_groups
              make.defaults
              package.mask
              package.unmask
              package.use
              package.use.force
              package.use.mask
              package.use.stable.force
              package.use.stable.mask
              profiles.desc
              repo_name
              thirdpartymirrors
              use.desc
              use.force
              use.local.desc
              use.mask
              use.stable.mask
              use.stable.force

       /usr/share/portage/config/
              make.globals
              repos.conf
              sets

       /var/cache/edb/
              misc internal cache files

       /var/db/pkg/
              database to track installed packages

       /var/lib/portage/
              config
              world
              world_sets