Custom AME for iAssets

I have a question about how the iAsset Rules work with a custom AME rule.  You have to setup an iAsset rule and the rule requires you to select an approval method and an approval type.  When I create a custom AME rule, does the rule have to include the approval method and approval type conditions?  OR can I just put my condition in which is based on a value in a DFF.....and the action type would be the approval chain of authority and the approval group would be a specific user.  AND what about the Releasing and Receiving Approver