People who finish an answer with "Didn't I?" or similar. If I had known the answer, I would not have asked the question in the first place.
People who give the impression that they are experts, but then proceed to display their lack of knowledge.
As above, but accompanied by foul and/or abusive language which serves to hide their lack of knowledge by persuading the listener to shut up.
People who assume you know what or whom they are talking about and then use indirect language to refer to it or them, rather than using direct names.
As an aside, I, along with all other members of management were once presented with a document to read prior to a meeting to discuss the documents contents. This document was almost completely made up from what could best be termed "management speak". It was, to be blunt, a load of rubbish. I created a list of what I considered were the major problems, and as an exercise, took one paragraph, rewrote it in plain English, and thereby reduced the paragraph length to 75% of the original. At the meeting, I presented my list of problems, and my rewritten paragraph. The document was never seen again.
Peter G. Shaw