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}}.
From an initialism: This is a redirect from an initialism to a related topic, such as the expansion of the initialism.
Use {{R from acronym}}instead for abbreviations that are pronounced as words, such as NATO and RADAR.
Use {{R from short name}}instead for the initials of a person's name.