return $XHTML?"\L<br\E$attr />":"\L<br\E$attr>" unless @_;
my($tag,$untag) = ("\L<br\E$attr>","\L</br>\E");
my @result = map { "$tag$_$untag" } 
    (ref($rest[0]) eq 'ARRAY') ? @{$rest[0]} : "@rest";
return "@result";