doubt about method for stripping tags

I have a doubt about this method inside Nop.Core.Html

        /// <summary>
        /// Strips tags
        /// </summary>
        /// <param name="text">Text</param>
        /// <returns>Formatted text</returns>
        public static string StripTags(string text)
        {
            if (String.IsNullOrEmpty(text))
                return string.Empty;

            text = Regex.Replace(text, @"(>)(\r|\n)*(<)", "><");
            text = Regex.Replace(text, "(<[^>]*>)([^<]*)", "$2");
            text = Regex.Replace(text, "
(&#x?[0-9]{2,4};|&quot;|&amp;|&nbsp;|&lt;|&gt;
|&euro;|&copy;|&reg;|&permil;|&Dagger;|&dagger;
|&lsaquo;|&rsaquo;|&bdquo;|&rdquo;|&ldquo;
|&sbquo;|&rsquo;|&lsquo;|&mdash;|&ndash;
|&rlm;|&lrm;|&zwj;|&zwnj;|&thinsp;|&emsp;
|&ensp;|&tilde;|&circ;|&Yuml;|&scaron;|&Scaron;)", "@");

            return text;
        }

Why the html special chars are replaced with an @ ? (last regex.replace line)

Thanks for any help.

Ps
regex pattern has been word wrapped for readability.