Is a "404 redirect" a legitimate redirect?

Question

I have a situation where some users may come to mistyped pages, from links, etc. In most situations I can determine the correct page that should be displayed, so I want to redirect to the correct URL.

Is a 301 Redirect appropriate in this case. 301 means "Moved Permanently", but in this case the document wasn't there in the first place. Is it legitimate to set a 404 Not Found header, then redirect to the correct URL?

Answer 1

I'd use 301. Moved permanently is appropriate in that it tells the accessed page is not there and never will be. If someone has a link to that page, they then know they should update the link.