Wikipedia:Red link
A red link, which looks like this, is a link to a page on Wikipedia that has not been created yet. Many of these pages can be found at "most wanted articles." Red links, as the name suggests, are always red. It is useful in changing article text to create a red link to show that a page will be created soon or that an article should be created for the topic because the subject is notable and verifiable. One study conducted in 2008 showed that red links helped Wikipedia grow.[1]
Red links in articles
Good articles
The Wikipedia:Requirements for good articles says a good article may have some red links or no red links, but not many red links.
Very good articles
Very good articles should have no red links, because they link to pages that do not exist, and should first be created.
Needed basic articles
For a long list of "basic encyclopedia articles" (10,000), see: Vital articles - expanded. Many topics on this list need an actual article. Redlinks for them may encourage editors to create articles.