gentoo-overlay/sys-apps/net-tools/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
<herd>base-system</herd>
<use>
 <flag name='old-output'>use old ifconfig output style (useful for when new output breaks scripts)</flag>
</use>
</pkgmetadata>