title: What characters are unsafe in query strings?
body: <p>I need to prevent the characters that cause vulnerabilities in the URL.</p>
  <p>My sample URL is <em>http://localhost/add.aspx?id=4;req=4</em>.</p>
  <p>Please give the list of characters that I need block.</p>
  <p>I am using an <a href="https://en.wikipedia.org/wiki/ASP.NET" rel="nofollow noreferrer">ASP.NET</a> web page. I am binding the information from an <a href="https://en.wikipedia.org/wiki/Microsoft_SQL_Server" rel="nofollow noreferrer">SQL Server</a> database.</p>
  <p>I just want to list the characters to stay away from <em>hackers</em> to enter unwanted strings in the URL.</p>