Comment followed.
You can configure the software to resolve these references internally (by creating "dummy" objects). However, you cannot request "selective mirroring" for a particular types of objects.
What happen if you don't want to share some of the person objects ? At least, I believe APNIC has a policy to guard private information so they may not want to mirror the maintainer and person objects.
Referential integrity needs to be satisfied only within a single source. That is TEST1-MNT with RADB source and TEST1-MNT with the RIPE one are in fact different objects.
How about AS3561 in RIPE, ARIN and APNIC ? In reality this is the same AS ( assigned by ARIN but need to be present in RIPE and APNIC as well ) And this will be a route creation problem, we will need to register some route objects in RIPE that originates from AS3561 very soon. Ping Lu Cable & Wireless USA Network Tools and Analysis Group W: +1-703-292-2359 E: plu@cw.net