Fonts should be embedded for any text that may be edited at runtime, other than text with the "Use Device Fonts" setting. Use the Text > Font Embedding command to embed fonts.
<gal>
  <image file="image0.jpg">
    <Big>image1.big.jpg</Big>
    <description>Picture of a book</description>
  </image>
  <image file="image2.jpg">
    <Big>Gallery/large/large2.jpg</Big>
    <description>Picture of a spindel of blank DVDs</description>
  </image>
  <image file="imagec3.jpg">
    <Big>Gallery/large/large3.jpg</Big>
    <description>Picture of a stick of RAM</description>
  </image>
  <image file="image4.jpg">
    <Big>Gallery/large/large4.jpg</Big>
    <description>Picture of Headphones</description>
  </image>
  <image file="image5.jpg">
    <Big>Gallery/large/large5.jpg</Big>
    <description>Picture of an Android phone</description>
  </image>
  <image file="image6.jpg">
    <Big>Gallery/large/large6.jpg</Big>
    <description>Picture of a computer Keyboard</description>
  </image>
</gal>