This page illustrates how some categories of articles can be categorized in larger categories by means of combinatorics, binomial expansion, and Pascal's triangle. The section "One factor" is included for continuation of the pattern.
The pattern can be complicated by intermediate categories with names having phrases such as "by nationality" (or "by country"), "by religious status", "by sex", "by occupation", "by employment status", and "by marital status".
The guidelines at Wikipedia:Category names might not apply universal consistency to the order of elements in category names.