SYSML2 — Semantics of transfers across interfaces

In 7.16.1 Actions Overview, in the "Bindings and Flows Between Actions" section, it states in the last paragraph (italics added):

A send action usage includes an expression that is evaluated to provide the values to be transferred, and it specifies the destination to which those values are to be sent (possibly delegated through a port and across one or more interfaces – see also 7.12 and 7.14 on interfaces between ports).

However, the semantics of "delagation across an interface", per the italicized part above, are not described in 7.12 or 7.14, nor are they specified in 8.4.10 Interfaces Semantics.