nls - Add Native Language Support (using gettext - GNU locale utilities)
readline - Enable support for libreadline, a GNU line-editing library that almost everyone wants
scd-shared-access - Allow concurrent access to scdaemon by multiple apps from same user. Useful if you want to use scdaemon with gnupg and for example NitroKey.
selinux - !!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur
smartcard - Build scdaemon software. Enables usage of OpenPGP cards. For other type of smartcards, try app-crypt/gnupg-pkcs11-scd. Bring in dev-libs/libusb as a dependency; enable scdaemon.
sqlite - Add support for sqlite - embedded sql database
ssl - Add support for SSL/TLS connections (Secure Socket Layer / Transport Layer Security)
static - !!do not set this during bootstrap!! Causes binaries to be statically linked instead of dynamically
test - Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)
tofu - Enable support for Trust on First use trust model; requires dev-db/sqlite.
tools - Install extra tools (including gpgsplit and gpg-zip).
usb - Build direct CCID access for scdaemon; requires dev-libs/libusb.
user-socket - try a socket directory which is not removed by init manager at session end
