This page describes Category:All, the topmost category. All other categories should be contained within it; each other category has a corresponding page that explains what it is and shows its subcategories. Nothing should be categorized as Category:All directly. Assigning a subcategory to any page automatically assigns the page to the parent categories of that subcategory. For example, there is no need to classify a page describing a bacterial pathogen as both Category:Bacterium and Category:Agent; classifying it as Category:Bacterium automatically classifies it as Category:Agent, Category:Organism, and Category:All as well.
QMRAwiki uses many different categories to describe its content. To visualize all the (sub)categories in CAMRAwiki, click the [+] and [-] symbols below to expand or collapse branches of the category tree. Numbers in parentheses indicate the number of subcategories within a parent category.
To assign a category to a page, edit that page and type this at the bottom: [[Category:Your Category Name]]