Create a Custom Relationship

You can add your own custom relationship types that can be used when making product and category relationships This will provide users with a closed vocabulary of supported relationship types..

1. In the Core database, in the /sitecore/client/Sitecore/Applications/Merchandising Manager/Category/PageSettings/RelationshipsGroup,, add a new item of type CommerceContextMenuItem, or copy an existing item, and title it with the name of the relationship. For example, CustomRelationship.
2. Set the 'Click' field set to javascript:app.addRelationShip("<your relationship name>", "<Friendly relationship name>");
3. To add a custom relationship for products, in the Core database, in the /sitecore/client/Sitecore/Applications/Merchandising Manager/ProductDetail/PageSettings/RelationshipsContextMenu, add a new item of type CommerceContextMenuItem, or copy an existing item, and title it with the name of the relationship. For example, CustomRelationship.
4. Set the 'Click' field set to javascript:app.addRelationShip("<your relationship name>", "<Friendly relationship name>");