Peer association can be done with below code in content model

         
           
               
                  cm:avatarOf
                  false
                  false
             
               
                  cm:content
                  cm:hasAvatar
                  false
                  false
               

           
       


0 or 1 => mandatory = false and many = false
1 => mandatory = true and many = false
0 or more => mandatory = false and many = true
1 or more => mandatory = true and many = true

Peer Association will be dispayed as below

Associations

Association Type	Target Reference	Target Type
cm:avatar	workspace://SpacesStore/6f9795fa-0e75-42cc-af9f-b543eda4804f	cm:content