Route domain ID

I have a deployment of a few partitions (common, a, b), with no non-default route domains. If I create a new partition, and create a route domain in it, what route domain would partitions a & b be in then?

 

Any gotchas in doing that?

 

This is a 10.2.4 system. Any existing nasty bugs with RD in this version?

 

Regards,

 

 

 

Jie