Sometimes we need to remove our pages from search results and keep them from showing up there. Discontinued product, a bio of a colleague who just left the company or any irrelevant content are some examples of web pages we don’t want to show up on search results.
We might wonder what happens if we ask Google to remove our URLs from its index database, and continue to allow it to be crawled and indexed through existing links from other pages within our sites. SE Roundtable has a short story about this.
If we remove pages from Google index, we must also ensure that it won’t crawl back there by enforcing redirections, robots.txt or any means of blocking the crawling of such pages. Otherwise, Google will place these pages back to its index database 90 days after it is removed.
For more information, read Google’s help page.