Documentation for COPY Operator

I've a couple of questions regarding the COPY operator.

1. What is the difference between using the parameter SOURCE_KFID and PRE_SOURCE_KFID?

2. Can there be only one SOURCE_KFID for multiple TARGET_KFIDs? In other words, if KF-TEST has to be copied to KF-TEST1 and KF_TEST2, what is the most optimal method to do that?

Is there any documentation for configuring the COPY operator?

Thanks in advance,

Chendur