Does Unity include unreferenced scene assets in a build?

I have a client/server project, with a client scene and server scene.

The server scene contains the world terrains. I do not want to packet this in the client builds.

If I only build the client, will Unity include the terrains, even though the client does not have a reference to them in any way at build time? The server sends this information via tcp upon login.
Thanks!

Short answer: no (from my experience)

Long answer:
I just tried this out a couple days ago… I put 10-20 MB worth of graphics in my project and made a scene. I did not add the scene to the list of scenes in the build. In X-Code the size of the app did not increase.