  Wikipedia is an encyclopedia, not a dictionary, but that's besides the point.  I agree: the element phosphorus is bound to be looked up more often than Phosphorus meaning Venus and so that article should take priority (in terms of where the user is taken when they search). However, Wikipedia is not designed to be used purely by Wikipedia editors or those clued up with its conventions (nor those willing to take the time to discover them), but by anybody who wants quick and helpful access to a topic. Is such a person likely to expect to find a footnote at the bottom of the element article - I certainly don't think so. I would have thought such a person would give up at that point and look elsewhere. I don't think such a person would expect the topic they're searching for to be a footnote to something entirely different. However, if the 'dab' (is that an official term?) is at the top of this article, this certainly isn't a problem.  I think it's poor practice - even if it is a general practice - to place disambiguation notices (I don't see why their 'significance' is a factor; either they're so insignificant they don't merit an article, or they do and hence shouldn't be hidden away) at the bottom of articles, since this makes the task of the user so much harder, whereas surely an encyclopedia should strive to make access to information as easy as possible.  How relevant the links to the page are I'm unsure: I would have thought many people access information by entering search terms, rather than coming from a different page, and so will not have the clarification of the article's name you seem to imply.   