#!/usr/local/bin/perl -l
#
use strict;
use warnings;

my $rxSplit = qr
   {(?x)
       (?<=[^<])
       (?=[<])
       |
       (?<=[>])
       (?=[^<])
   };

my $html =
   q{<tag ref=1>Start<tag ref=2>and more</tag>and end</tag>};

my @elems = split m{$rxSplit}, $html;

print for @elems;

##</code><code>##

<tag ref=1>
Start
<tag ref=2>
and more
</tag>
and end
</tag>