As pointed out in the preface of the book, its format is homage to the late Richard Stevens who wrote a great series of books on Unix and TCP/IP programming in the 1990s. After carrying around TLPI for several weeks I am beginning to think that dividing TLPI into several volumes (like Richard Stevens did) would be a good idea.
Having fought with System V IPC I think that I'll skim the IPC sections. Besides I use inotify, flock and tmpfs to cover my current IPC needs. And TLPI is the first book that I have seen to cover those three subjects.