Contract distribution in SRM

Hi

I want to distribute the Global Outline Agreements from SRM to R/3. When I click on Release Button the contract is supposed to be distributed to the R/3 system. What is the outbound IDoc that gets triggered at the time of release. Because I do not see any IDoc being created in WE02.

Also does BLAORD actually creates the contract in R/3. Then what is the significance of maintaining BLAREL in the partner profiles in both outbound and inbound parameters.

Also If I want to make changes to the contract in R/3, will the changes get distributed to SRM as well.

Also what is the difference in Functionality between GOA and Purchase Contract.

Regards

Raj