To a related topic: This is a redirect to an article about a similar topic.
Redirects from related topics are different than redirects from related words, because a related topic is more likely to warrant a full and detailed description in the target article. If this redirect's subject is notable, then also tag it with {{R with possibilities}} and {{R printworthy}}.
To a section: This is a redirect from a topic that does not have its own page to a section of a page on the subject. For redirects to embedded anchors on a page, use {{R to anchor}}instead.
From a cross-project redirect: This is a redirect from a title linked to an item on Wikidata. The Wikidata item linked to this page is Variola virus (vaccinia) (Q11877169).