Robots.txt Query String - Couldn't Disallow <p>I have url </p> <p><a href="http://www.website.com/shopping/books/?b=9" rel="nofollow">http://www.website.com/shopping/books/?b=9</a></p> <p>I have disallow /?b=9 from robots.txt</p> <p>as</p> <p>User-agent: * Disallow: /?b=9</p> <p>But when i test this from Google Webmaster Robots.txt Test Tools. </p> <p>Showing allowed while it should be display disallowed...</p> <p>Please tell any wrong with my robots.txt</p> <p>URL - <a href="http://www.website.com/shopping/books/?b=9" rel="nofollow">http://www.website.com/shopping/books/?b=9</a></p> <p>User-agent: * Disallow: /?b=9</p> <hr> <p>Also </p> <p>there /?b=9 this will be same in all cases and /shopping/books/ will be change with different category.</p> <p>How to Block this types of string ?</p> <p>Disallow: /?b=9 </p> <p>Is it correct ?</p>