with

_discussiontools as (
select it_id, it_itemname, itp_page_id, itid_id
from discussiontools_items
join discussiontools_item_pages
	on itp_items_id = it_id
join discussiontools_item_revisions
	on itr_items_id = it_id and itr_revision_id = itp_newest_revision_id
join discussiontools_item_ids
	on itid_id = itr_itemid_id

join page on page_id = itp_page_id and page_latest = itr_revision_id

-- Ignore placeholder headings on pages with no headings, which would all be duplicates of each other
where it_itemname != 'h-'
-- Ignore items where the newest revision containing them is not the latest revision of the page
and page_id is not null
-- Ignore items which are transcluded from another page
and itr_transcludedfrom is null
),

_counts as (
select
	left(it_itemname, 1) as type,
	number_of_copies,
	count(*) as number_of_items,
	group_concat(it_itemname order by rand() separator ' ' limit 3) as examples
from (
select it_itemname, count(*) as number_of_copies
from _discussiontools
group by it_itemname
) x
group by type, number_of_copies
)

select number_of_copies, number_of_items, examples from _counts
where number_of_copies > 1
and type = 'c'
order by number_of_copies desc