Using the B flag, non-alphanumeric characters in backreferences
will be escaped. For example, consider the rule:</p>
<pre><code> RewriteRule RewriteRule ^(.*)$ index.php?show=$1 </code></pre>
- <p>This will map <code>/C++</code> to <code>index.php?show=C++</code>.
+ <p>This will map <code>/C++</code> to <code>index.php?show=/C++</code>.
But it will also map <code>/C%2b%2b</code> to
- <code>index.php?show=C++</code>, because the <code>%2b</code>
+ <code>index.php?show=/C++</code>, because the <code>%2b</code>
has been unescaped. With the B flag, it will instead map to
- <code>index.php?show=>/C%2b%2b</code>.</p>
+ <code>index.php?show=/C%2b%2b</code>.</p>
<p>This escaping is particularly necessary in a proxy situation,
when the backend may break if presented with an unescaped URL.</p>
</dd>