User blog comment:MisterWoodhouse/This Month at Fandom - November 2019/@comment-24687156-20191204103506/@comment-38078079-20191204104909

The full article is here: User Blog:Brian Linder

It essentially means that this specific anime wiki is "official", as in it has the backing of the rights holders as something they think can represent their work to a high-standard. It means the wiki likely is very professional, has accurate information, and - potentially - may even have content that comes direct from the source (as they may work with the source providers).

It's a sign that you can trust that wiki, as the content owners trust them.