Question Where to find Region Identifiers that are returned in QoS results?

Hello,

We have a game that we want to launch in North America, Europe and Asia. But if player count is low we want to enable cross regional play, if the player chooses to.

When we use

Code (CSharp):

1.  var qosResults = await QosService.Instance.GetSortedQosResultsAsync(serviceName, regions);
2.  

We get returns with ID with Ids like..

Code (CSharp):

1. "daffc8ce-ef67-11e9-8a23-0242ac110002",
2.                     "b051f066-8d9a-11eb-8db5-0242ac110002",
3.                     "a952f32c-593c-11ed-8347-6e557699aa6f",
4.                     "8894b542-ef65-11e9-8cfb-0242ac110002"

Question1: What are these Region IDs, and where can I find them? I have tried to search and figure it out but am stumped on how I can effectively use them.
Question 2: How would I go about if I want to limit a player to one region (say, Australia)? My assumption right now is that I would only need to find the Region id corresponding to Australia in the query and only include those results in the QoS that I attach to the ticket creation. However, I need the IDs listed above to filter, and I don't know where to find them.

Thanks!