I have a simple example: RewriteEngine on RewriteRule ^first.html$ second.html In this case a user can access the second.html page if he type domain/first.html or second.html. I am wondering if google or other search engine can find out that domain/second.html page exists even if I don't put any link to this page. Because that would mean duplicate content in the page first.html (which is actually second.html but user or bot can not know that) and second.html. What do you think about that? Are there any worries for that?