Part 2: Relationship atom entry rel 'via'

Part 2: section 7.1 states:

via: Points to the originating atom entry document if available that contained the relationship link the client followed to get to this collection.

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Can via always point to either the source (preferable) or target atom entry of the relationship? rather than determined by the route taken by the client, as this is not always easy to determine, if at all.