The data from component suppliers on lay-out for solderability are in general given with the assumption that only that particular component is used. The real world shows us that this is seldom the case. This means that in a lot of cases, using the "recommended" lay-out rules, one often get poor soldering results. The way to improve soldering quality, is to recognize the effect of other components on the same board and add some common sense to the lay-out rules.
The attached article is meant to help recognize under which conditions common sense has to be put in.