Global USE flags

Flag Description Packages
doc Install API documentation 3
headless-awt Don't install the X backend for AWT, needed by some GUIs (used to be X flag) 4
test 3

Category USE flags

dev-java

Flag Description Packages
alsa 3
cups 3
debug 2
selinux 3
source Install JVM sources 2

dev-libs

Flag Description Packages
static-libs 2

Local USE flags

dev-dotnet

dotnet-runtime-bin

Flag Description
lttng Install support libraries for LTTng with .NET.

dev-java

openj9-openjdk

Flag Description
ddr Enable Direct Dump Reader
javafx Import OpenJFX modules at build time, via <pkg>dev-java/openjfx</pkg>
jbootstrap Build OpenJDK twice, the second time using the result of the first
jitserver OpenJ9 JITServer support
lto
numa Enable NUMA support using sys-process/numactl (NUMA kernel support is also required)
systemtap Enable SystemTAP/DTrace tracing

dev-libs

libdwarf

Flag Description
decompression Enable decompression with zlib/zstd
dwarfexample Install dwarfexample bin
dwarfgen Install dwarfgen bin

openssl

Flag Description
asm Support assembly hand optimized crypto functions (i.e. faster run time)
cpu_flags_x86_sse2
fips Enable FIPS provider
ktls Enable support for Kernel implementation of TLS (kTLS)
quic
rfc3779 Enable support for RFC 3779 (X.509 Extensions for IP Addresses and AS Identifiers)
sctp
tls-compression Enable support for discouraged TLS compression
vanilla
weak-ssl-ciphers Build support for SSL/TLS ciphers that are considered "weak"

mail-client

astroid

Flag Description
embedded-editor Embedded editor
plugins Plugins
profile
terminal Embedded terminal

net-mail

notmuch

Flag Description
apidoc Provide doxygen generated API docs
crypt Support decryption and verification of PGP/MIME messages and in Emacs UI - encryption; support also S/MIME signature verification since version 0.22
emacs Install Emacs UI (the main one)
mutt Install helper script for Mutt
nmbug Install experimental tag sharing / pseudo-bug-tracking script for Notmuch (see http://notmuchmail.org/nmbug/)
python

sys-boot

limine

Flag Description
abi_x86_32
abi_x86_64
amd64
bios Enable BIOS/MBR boot support.
bios-cd Enables BIOS boot support for CDs.
bios-pxe Enables BIOS PXE boot support.
uefi
uefi-cd Enable building cd-efi.bin using <pkg>sys-fs/mtools</pkg>. This flag was previously known as eltorito-efi.
x86