I've read everything I can get my hands on about narrowboating and the canals. On several blogs and in some lovely books about peoples' experiences on the canals there have been some daunting stories of angry fishermen or other boaters - often completely unfairly.
I also notice this week that Gypsy Rover (AU) had an annoying experience with bad canal manners.
It got me thinking about the rules out there that we might not be aware of. When we hired in 2007 we really were told very little about what we should or shouldn't do. They provided a boaters handbook but not everyone would bother to read the 40 pages. Here's a link to the handbook.
I found this unofficial list of etiquette matters.