D.S.A. I just begining to learn PHP, MySQL, also .htaccess and regEx. Its so many things which I dont understand . So please help me.

I have file .htaccess contains:

RewriteBase /
RewriteRule ^([a-z0-9-]+)\.xhtml$ index.php?read=yes&url=$1

the problem is when I load page:

/my-post-page.xhtml
and
//////my-post-page.xhtml

are truely same page.

What should I do to make sure that permalink with format "/my-post-page.xhtml" is the right?