BQM 597
What does Black have in the corner?
This site's J Group page gives White a supporting stone behind White's hane, and in his youtube video on the J Group (roughly 6:19), Nick Sibicky said "you need to have something", and put a white stone on the third row several columns to the right of White's hane.
I don't see why White can't just handle the top like "Hane, again" from Preventing escape on the first line.
Bill: In "Go no Tsume to Yose" (Tsumego and Yose), vol. 5 of Sakata's Killer of Go series, the 11th corner tsumego problem has this form: