Where to put interface blocks?

[Roche Pso]

When doing a logical architecture I use proxy ports on blocks and type them with interface blocks.

I am a bit unsure where the interface blocks are best put in the model structure and shown on diagrams.

In this example block A is made from B and C. There is an external interface for A, provided by C but not fully defined which part of C yet. There is an internal interface between B and C.

So I have put proxy ports on A and B, and two on C. The port on A and one of the ports on C are typed by an "external if" interface block, and the second port on C and the port on B are typed by an "internal if" interface block (the port on C is conjugated)

At the moment the interface blocks are shown on the bdd for block A, floating on the diagram below the A-B-C construct. Is there a better place to put them and should they have some kind of ownership link to A,B or C?? They look odd just floating there with no connections.

In the project structure they are in the same package as A. Again, is this ok or is there a better place to put them?