Fuse for ignition coil circuit?
 

My car is an '88 3.2 Carrera. I was looking in the Bentley manual at page 280-7 and they were pointing out the supposed location of a fuse on the panel for the ignition coil. When I look at the fuse diagram, there's no indication that any of those fuses are meant to fuse the coil circuit.... Mistake maybe?
I know on my '70 Beetle, the ignition circuit is unfused and what I and lots of careful owners have done is to add a fuse to that circuit just in case.
I thought I may have seen some postings about people fusing the coil circuit on their Porsches, but I can't find a posting. Is this a problem that Porsche owners have taken care of, and if so if you have a link to a posting on this forum regarding the procedure, I'd appreciate seeing it.