I modified you subroutine 'PassMe' so that only references to a hash are pushed into the array @data. (I named it 'other_hash', but you should definitely rename it!). This should ease the maintenance.

sub passMe
{
    my @data = ();
    my %other_hash = (
        position => 'annotations',
        sid      => $sid,
        navigator_link =>
          '<a id="expand_nav" onclick="Element.hide(\'expand_nav\');">
+[brief]</a>',
        annotations_detail_link =>
          q|[<a id="sed" onclick="Element.hide('sed'); Element.show('h
+ed'); show_experiment_details();"> experiment details</a>]|,
        template => $tmpl
    );

    push(
         @data,
         {
          \%params,      
          \%extend_params, 
          \%basics,
          \%annotations, 
          \%navigator,     
          \%other_hash
         }
        );

    return \@data, $ID;
}
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