What are darkpool signature prints?

Darkpool prints that are reported with almost 24 hour delay are considered as signature prints. Typically, their price is higher or lower than the price range of today, which lets us gauge whether they were bought or sold positions. For instance, if a darkpool print took place 24 hours ago and price is lower than the print's price, we can make an assumption that it could have been a bearish position. The opposite goes for bullish trades.