inRiver LinkType handling
The inRiver entities are processed by the connector by handling the connected inbound and outbound links to them. For example, when exporting an inRiver channel node as a Litium Studio product group, the connector is actually processing the ChannelNodeChannelNode link. When exporting an inRiver channel node as a Litium Studio assortment, the connector is actually processing the ChannelChannelNode link.
inRiver Links and LinkServices in the connector
As presented in the sequence diagrams in the article on architecture, the logic of exporting inRiver entities is implemented in ILinkService classes. Each link type may have a class to handle it.

Not all inRiver link types need a specific LinkService class in the connector. For example, the item shown with the green arrow is treated by default as a Product-Product Litium Studio relationship, and is handled by the ProductProductLinkService class in the Relationships folder.
Its the ServiceFactory class that determines the specific ILinkService class implementation for a given a inRiver link type. It has the ILinkService GetLinkService(string linkTypeId) method that gets called when the program execution need to handle a inRiver link.
Determining which ILinkService class will service a inRiver link
The first choise is given to the LinkTypeIdAttribute class attribute, and when this attribute is set, if the linkTypeId of the inRiver link matches the class attribute of this class, its instance is provided to handle that link type.

When the linktypeId of a link does not directly match with the name of a defined ILinkType class instance, then the Service Factory checks whether the LinkTypeId is categorized to behave as a pre-defined behaviour from the connector settings.

The connector already has ILinkService classes for the predefined behaviours above. Therefore the appropriate handler link service instance will be picked.
If the connector setting does not contain the link type id, then the link is considered a resource or a information link if the link target is a Resource or a Specification,
and as a relationship otherwise. The exact relationship is based on source and target entity types of the link.
\Src\Litium.Studio.AddOns.Inriver\ServiceFactory.cs :: MapLinkTypesToLinkServices() method is doing this mapping.