gentoo-overlay/gnome-base/gdm/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer type="project">
    <email>gnome@gentoo.org</email>
    <name>Gentoo GNOME Desktop</name>
  </maintainer>
  <use>
    <flag name="bluetooth-sound">Allow loading of bluetooth sound modules. This may be necessary for accessibility screen readers, but may cause bluetooth sound issues for users logging in.</flag>
    <flag name="fprint">Enables experimental fingerprint authentication using <pkg>sys-auth/fprintd</pkg></flag>
    <flag name="plymouth">Enable support for smooth transition from <pkg>sys-boot/plymouth</pkg></flag>
  </use>
  <upstream>
    <remote-id type="gnome-gitlab">GNOME/gdm</remote-id>
  </upstream>
</pkgmetadata>