app-admin/collectd:cd_zfs_arc - Build the zfs_arc input plugin
app-admin/collectd:contrib - Install user-contributed files in the doc directory
app-admin/vlogger:dbi - Enable support for DBI
+app-arch/zpaq:optimization - Install additional files required to support ZPAQ's optimized compression mode.
app-backup/darbackup:dar64 - Enables --enable-mode=64 option, which replace infinite by 64 bit integers
app-backup/fsarchiver:gcrypt - Enables cryptography support via libgcrypt
app-backup/fsarchiver:lzma - Enables LZMA compression
media-gfx/openvrml:xembed - Build the XEmbed container control
media-gfx/synfigstudio:fmod - Enables support for using mod files for audio support
media-radio/ax25-tools:X - Enable some x based configuration tools.
-media-radio/drm:hamlib - Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the radio in use
media-radio/fldigi:hamlib - Enables support by the Hamlib amateur radio rig control library to get/set frequency and mode of the ham radio in use
media-radio/grig:hardware - Enable hardware IO
media-radio/unixcw:ncurses - Enables building the curses based morse code tutor program 'cwcp'.