nlwiki Anomalies with "IJ"

SQL

USE nlwiki_p;
/*SELECT 
	page_namespace AS 'src-ns', page_title AS 'src-title', 
	pl_namespace AS 'tgt-ns', pl_title AS 'tgt-title'
FROM `pagelinks`, `page` ps
WHERE 
	pl_namespace NOT IN (2,3) AND 			# no links to user namespaces
	pl_title REGEXP '^Ij' AND		# target title starts with 'Ij'
	NOT EXISTS (					# target page doesn't exist
		SELECT * FROM `page` pt WHERE pt.page_namespace=pl_namespace AND pt.page_title=pl_title
	) AND
	EXISTS (						# correctly capitalized target does exist
		SELECT * FROM `page` pt WHERE pt.page_namespace=pl_namespace AND pt.page_title=BINARY CONCAT(_UTF8MB4 'IJ', SUBSTRING(pl_title, 3))
	) AND
	pl_from=ps.page_id 				# acquire source page title
ORDER BY pl_namespace, pl_title*/
SELECT pt.page_namespace AS 'ns', pt.page_title AS 'title', pt.page_is_redirect AS 'redir'
FROM redirect, page pt
WHERE
	rd_from=pt.page_id AND
    pt.page_title REGEXP '^IJ' AND
    ((
        pt.page_is_redirect=0 AND
        NOT EXISTS (
            SELECT * 
            FROM redirect, page ps
            WHERE 
                rd_from=ps.page_id AND
                rd_namespace=pt.page_namespace AND 
                rd_title=pt.page_title AND
                ps.page_title=BINARY CONCAT(_UTF8MB4 'IJ', SUBSTRING(rd_title, 3))
        )
    ) OR (
        pt.page_is_redirect=1 AND
        NOT EXISTS (
            SELECT * 
            FROM redirect rs, redirect rt2, page ps, page pt2
            WHERE 
          		pt2.page_id=rt2.rd_from AND
                rs.rd_from=ps.page_id AND
                rs.rd_namespace=pt2.page_namespace AND 
                rs.rd_title=pt2.page_title AND
                ps.page_title=BINARY CONCAT(_UTF8MB4 'IJ', SUBSTRING(rs.rd_title, 3))
        )
    ))
ORDER BY ns, title
SQL

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