If you look at the decisions of the various ethics commissioners across the country, plus the annual reports of the ethics commissioners, which really summarize in such a way so as not to violate confidences, you'll get, from the advice they're giving to people who come to them for advice, I think a pretty good idea of what is meant by “friend”. It is someone who is more than an acquaintance, someone who you'd like to assist in terms of “you scratch my back, I'll scratch yours”. I think it would be kind of dangerous to go into a clearer definition of what a friend is, because it could lead to unnecessary loopholes.
On February 4th, 2013. See this statement in context.