gentoo-overlay/dev-java/oracle-jdk-bin/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <herd>java</herd>
  <longdescription>Oracle Java SE Development Kit, Official Binary Distribution</longdescription>
  <use>
    <flag name="derby">Enable Installation of Bundled Derby (Java DB)</flag>
    <flag name="jce">Enable Java Cryptographic Extension Unlimited Strength Policy files</flag>
  </use>
</pkgmetadata>