Item Relationship Type "Accessory"

Oracle standard Item Relationship setup does not list a type called "Accessory". For a FG Item sold, an 'Accessory' is defined as "An Item which does not provide functionality if purchased by itself but can enhance the function or performance of the FG product to which it is added to or being sold with. Accessories are listed along with the main FG Item and are charged additional.

Which standard Oracle out-of-box Item Relationship Type will fulfil the above definition? Is it possible to define a new Item Relationship Type called "Accessory" which will solve the above business scenario?

Thanks in advance for any lead/suggestion on this.