noindex only tells the search crawlers to not include the page in the index but still allows for them to crawl the page. nofollow will tell the crawlers to not crawl the page.

robots.txt will accomplish this as well but both I think would be overkill.

That does answer my question partly. How do you handle the cached URL for the original 301 that points to the invalid URL?

Example. www.bob.com/hello points to www.bob.com/directory/folder/file.aspx

It needs to now point to www.bob.com/directory/folder2/file2.aspx

If browsers and search engines cache the first 301 since it's meant to be permanent, visitors that have been to the first URL will not get passed off to the new one.

We have a vanity URL that as recommended is using 301 http code, however it has been discovered the destination URL needs to be updated which creates a problem since most browsers and search engines cache 301 redirects.

Is there a good way to figure out when a vanity should be a 301 vs 302/307?

If all vanity URL's should use 301, what is the proper way of updating the destination URL?

Is it a good rule of thumb that if the vanity URL is only going to be temporary and down the road could have a new destination URL to use 302, and all others 301?

Cheers,