gentoo-overlay/media-fonts/corefonts/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <herd>fonts</herd>
  <use>
    <flag name="tahoma">Also install the Tahoma font. Due to the lack of a free
      bold variant, this may render badly. See bug 184790.</flag>
  </use>
  <upstream>
    <remote-id type="sourceforge">corefonts</remote-id>
  </upstream>
</pkgmetadata>