# Define a page
page <page key>
{
   toolbar standard;
};
# Define a standard toolbar
toolbar standard
{
   item
   {
      <item config>
   };
};

##</code><code>##

# Encounter the toolbar standard; line in the page config

# Doesn't actually do anything
$page->{<page_key>}{'toolbar'} = $toolbar->{'standard'};

# complains about standard getting re-defined
$toolbar->{'standard'} ||= {};  # also tried undef and dummy value instead of {} with no luck
$page->{<page_key>}{'toolbar'} = $toolbar->{'standard'};

# $toolbar->{'standard'} is actually populated sometime after I process $page->{<page_key>}