/etc/portage/make.profile

The or  directories are usually symlinked to the correct profile in. Since it is part of Portage it may easily be updated or regenerated by running emerge --sync. It defines what a profile is (usually arch specific stuff).

Users who wish to have custom profile should make their own directory and populate it by hand. However, when wishing to override some settings, use (it supports all of the same file types that  does, except parent). Do not edit the settings in because they will be lost with the next emerge --sync. If both and  exist, then  will be preferred.

Any file in this directory, directories of other profiles or top-level "profiles" directory that begins with or  can be more than just a flat file. If it is a directory, then all the files in that directory will be sorted in ascending alphabetical order by file name and summed together as if it were a single file.

Examples: