Just past page 281 of Becky Chambers's delightful "the galaxy, and the ground within".

  Received Message
  Encryption: 0
  From: GC Transit Authority --- Gora System (path: 487-45411-479-4)
  To: Ooli Oht Ouloo (path: 5787-598-66)
  Subject: URGENT UPDATE

Looks like this multispecies universe has centrally-agreed-upon path addressing system.

You should check out Vernor Vinge's A Fire Upon The Deep for more fun examples of how intra-galactic communication would be labeled, with routes & such.

From this book in particular, I love the scene with everyone sitting around talking about how horrifying the concept of cheese is. The rest of the quartet is wonderful, with the second book (A Closed and Common Orbit) being the MVP IMO.