open I, shift or die "$!";

while (<I>) {
    /xml>/ and next;
    s/title>/h3>/g;
    s/bq>/blockquote>/g;     # <bq> instead of <blockquote>
    s/introduction>/blockquote>/g;
    s!<cpan>(.*)</cpan>![cpan://$1]!g; # <cpan>mod::name</cpan>
    s!<c>!<code>!g;  # <c>code</c>
    s!</c>!