a0494a2a_ng__404_Not_Found_Error__Files__Category
[Comments and examples] URL rewriting is often used to present human-readable addresses. These may include directory names (e.g. years, months and days for blog entries) which generate a not found error when requested independently. E.g. for /2010/10/26/Benign-Unexpected-URLs-Part-1-Missing-Files /2010/10 /2010/ [Category] 
URL Rewriting
Benign Unexpected URLs - Part 1 - Missing (404 Not Found Error) Files