Referring to books by author name instead of title
A fun linguistic quirk is that some mathematics books are referenced (on the Internet?) more often by a variant on author name than by title. For example, "Baby Rudin" for Walter Rudin's Principles of Mathematical Analysis as opposed to Walter Rudin's Real and Complex Analysis ("Big Rudin"? I forget), or "Munkres" for James Munkres' Topology.
I wonder what other examples of this there are.