I found myself laughing quite loudly, and re-reading this passage to my wife to help her share in my enjoyment. I’m not sure I succeeded, but I will share with you all nonetheless.
The subject is conversation, and in the specific passage, the authors are beginning to illuminate the “presupposition pool”. Even more specifically, the idea that speakers naturally exclude or include content based on these shared concepts.
…Any speaker will necessarily make certain assumptions about his listeners and will fashion what he has to say accordingly. For example, he will not unnecessarily explain such technical terms as he may use unless he is fairly sure that explanation is required; the gratuitous supply of an unnecessary explanation may become part of the communication and may be perceived as patronizing. On the other hand failure to provide a necessary explanation may be perceived as deliberate one-upmanship, as exhibitionism, as (Chapter 3) sesquipedalian. Under these circumstances the listener may determine not to ask for clarification of the new word and so allow the communication to fail. In either case misunderstanding of the actual contents of the presupposition pool is likely to lead to an undeniable alteration in the character of the conversation.Linguistics & Biblical Interpretation, p. 258
Yes, I had to look up “sesquipedalian” (Yes, they did in fact define it in Chapter 3, right near the beginning, and yes, that knowledge went “in one ear and out the other”, so to speak). Yes, you should look it up, too. These are my kind of people.