Pretty sure the 8 is a job specific of the C1S/F6834A. Could be an additional non-standard key switch installed or some special feature. Most of the time it is not important unless you are working on a special feature. The S/F designates a S for straight line and F for field. For example there may be 5 jobs in the USA that use this diagram with some special feature. If wondering why the old Otis Prints had crazy symbols and did not match the Electrical Standard symbols. The answer is when Otis made wiring diagrams in the old days, those were symbols that could be made on a typewriter.