An pre-delegated domain test is a test performed on a domain that can (but need not) be fully published in DNS.
This can be very useful if you are considering moving your domain from one registrar to another. Let us take, for example, the domain example.se being moved from the name server ‘ns.nic.se’ to the name server ‘ns.iis.se’.
In this case, you could run an undelegated domain test on the domain (example.se) with the name server you are moving to (ns.iis.se) BEFORE you go through with the move.
When the test shows green, you can be fairly certain that your domain’s new home is able to answer questions about your domain. However, there may still be errors in the zone data that this test does not know.