A linguist explains the history and semiotics of internet communication. While some chapters sing out more than others, this book offers tremendously helpful insights about communication in the post-post-modern era.
Thanks to the internet and texting (and all of the irony, subtext, and various other linguistically subversive nuances one can communicate via those media) modern culture is experiencing what I consider could be the first stages of a hard fork in written communication. An early example might be a concept like Poe's Law, which arose to explain how entire demographics fail to see irony or sarcasm when clearly intended. The growing political bifurcation in the USA seems to be giving rise to noticeable differences in dialectic and language style.
Even the "language" of Bitcoiners with their rhetorically powerful memes and extensive use of vocabulary designed to be unintelligible to outsiders (e.g.: "few," "gradually, then suddenly," "hodler," US trash token" and so on) gives us a concrete example of how language can signal--and even serve to define--group membership.
When we've come to the point where the use of an eggplant emoji in the wrong context can be deeply embarrassing, I think it's safe to say that we are starting to see the development of an entire taxonomy of proto-languages online. This book will help you navigate these new frontiers.