gentoo-overlay/app-misc/lirc/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
<herd>media-tv</herd>
<use>
  <flag name='hardware-carrier'>The transmitter device generates its clock
    signal in hardware</flag>
  <flag name='transmitter'>Add transmitter support to some lirc-drivers
    (e.g. serial)</flag>
</use>
</pkgmetadata>