<Li> Multi-directional navigation . A category can contain multiple subcategories, and can also be part of several categories . Categories are organized within Wikipedia into a web of knowledge starting with Category: Wikipedia categories . </Li> <Li> Good for exploratory browsing of Wikipedia . </Li> <Li> Less susceptible to external linkspam than other types of pages, because only Wikipedia articles can be members of categories . </Li> <Li> Relatively unobtrusive in that they generally don't distract from the flow of the article . </Li>

Which list is an example of a category hierarchy