Referances VR vs. OR

Hi all,

I am trying to understand difference between Version Reference VR: and Object Reference OR: and relation between them. I think this is important when referencing to objects in Windchill. But I did not find any solid explanation in manuals so I ask for help if anybody can explain this I will appreciate it.

For example:

NEW object created, version A.1 oid is VR:wt.part.WTPart:125979 and OR:wt.part.WTPart:125980

after CHECKOUT

copy gets a new oid VR:wt.part.WTPart:125999 and OR:wt.part.WTPart:126000

the after CHECKIN

new version A.2 gets oid VR:wt.part.WTPart:125979 and OR:126000

and version A.1 has only OR:wt.part.WTPart:125980

It seems to me that OR references actual object and VR last version? And this is a bit of a problem because when using Query-Objects webject with obid as ATTRIBUTE you get VR not OR so how to get OR using webjects. On the other hand using listener to listen to events and using: final Workable wrkWTPart = (Workable) ((PersistenceManagerEvent)event).getEventTarget(); call you get OR of object not VR.

I am definitely confused, please help.

Thanks.