To change the default object privilege setting property of a user, basically it will revoke a list of default object privileges from a list of users or roles. These object privileges will not be granted to the specified user or role on the new objects whenever the owner creates them.
parseRevokeDefObjPrivCommand =  OMBREVOKE DEFAULT ( OBJ_PRIV | 
          OBJECT_PRIVILEGE ) "objPrivNameList" FROM ( USER "userOrRoleNameList" 
          | ROLE "userOrRoleNameList" ) [ FOR USER "QUOTED_STRING" ] 
     objPrivNameList =  "UNQUOTED_STRING" { "," "UNQUOTED_STRING" }
     userOrRoleNameList =  "QUOTED_STRING" { "," "QUOTED_STRING" }