Older entries:

• 404-Like Content In Google Webmaster Tools: Soft 404s | June 7, 2010
• Google Webmaster Tools "Not Found" Errors Won't Hurt Your Rankings | June 2, 2010
• Not Only Are 410 Response Codes More Permanent, They Are Faster | April 30, 2010
• Google: Large Number of 404s Doesn't Hurt You | March 29, 2010
• Remove Pages From Google ~Forever Using a 410 Status Code | January 27, 2010
• Google Now Treats 410 Status Code As "More Permanent" Than 404 Status Code | October 27, 2009
• Google Enhanced 404 Feature Gone? | July 8, 2009
• 404 Pages Should Not Return 200 Status Codes | March 20, 2009
• Google Search Engine Sports Broken Link, Few Notice | October 27, 2008
• Out of Stock? Don't Delete or Redirect That Web Page! | September 5, 2008
• Google Fixes 404 Widget Scripting Errors | August 21, 2008
• Google Enhances "404 Not Found" Experience, Creates Broken Page Experience Instead | August 20, 2008
• 404 or 301 Your Old Pages? Which is Best For SEO? | August 14, 2008
• What to Do When You Have a 404 Error | June 26, 2008
• Make Sure to Return the Right Response Code on 404 Pages | April 14, 2008
• del.icio.us Blocks Search Engine Spiders | February 18, 2008
• Google's Toolbar Reportedly Overwriting 404 Pages Across The Web | February 12, 2008
• Should Google Spice Up Their "404 Not Found" Pages? | January 30, 2008
• Ask.com Fixes Crawler Issue With Badly-Formed URLs | January 4, 2008
• Ask.com Crawler Inserting Url-Encoded Spaces in URLs Causing 404 Errors? | December 31, 2007
• Do Search Engines Prefer Default or Custom 404 Error Pages? | November 28, 2007
• Are 404 Errors Bad for SEO? | October 29, 2007
• Does Google Still Crawl 404 Not Found Pages? | March 9, 2007