Documenting the full functionality in the MSHT file

I'm trying to establish the full amount of options available in the Moonshot MSHT file. At the moment we have the standard file:

<?xml version="1.0" encoding="UTF-8"?>
<identities>
  <identity>
    <display-name>[i.e. John Smith from Camford University]</display-name>
    <user>[i.e. johnsmith]</user>
    <password>[i.e. correct-horse-battery-staple]</password>
    <realm>[i.e. camford.ac.uk]</realm>
    <selection-rules>
    </selection-rules>
    <trust-anchor>
      <server-cert>[sha256 fingerprint OR the base64 encoded representation of a root certificate in DER form used in the IdP's trust anchor]</server-cert>
    </trust-anchor>
  </identity>
</identities>

What other options should there be? I've spelunked through the code and found these:

<service>
<ca-cert>
<subject>
<subject-alt>

Am I correct in assuming that the first one is on the same level as <realm>, or does it fall under <rule>? And do the other three fall under <trust-anchor>?

We're documenting it here: https://wiki.moonshot.ja.net/display/TR/moonshot-webp+XML+Format