Translations:/etc/portage/make.conf/22/pl
From Gentoo Wiki
The FEATURES variable contains a list of Portage features that the user wants enabled on the system, effectively influencing Portage's behavior. It is set by default via /usr/share/portage/config/make.globals, but can be easily updated through /etc/portage/make.conf. Since this is an incremental variable, FEATURES values can be added without directly overriding the ones implemented through the Gentoo profile.
FEATURES="keepwork"
For more information, please see Portage features in the Gentoo Handbook and the FEATURES article. For a complete list of available features, see man 5 make.conf.