What linktypes can be associated across servers.

I need clarification on what link types can be linked across servers when a friendship is associated. The predefined linktypes such as Blocks/Depends on, Affected by Defect are those linktypes available for association across servers.  Both projects are ccm.  If you create custom link types if a friendship is created will those linktypes be available to link across servers?  The linktype "related Change request" is a defect considered a "related Change request" linktype?  Is the linktype defect only available for linking by QM projects? 

When I link using linktype "affected by Defect" the linktype on the other workitem is Affected Plan Item.  Is that correct is there a way I can change the association between those linktypes?