A new set photo from David Ayer's Suicide Squad shows that may be the files of Dr. Harleen Quinzel.
In any case, it's files from Arkham Asylum, marked for the City of Gotham Department Public Health Services.
What's interesting, perhaps, is that it appears these files are on a number of different subjects...so maybe it isn't only Harley and the Joker, but all of the Squad who have connections to Arkham.
Ayer will direct the film, which stars Jared Leto as The Joker, Margot Robbie as Harley Quinn, Will Smith as Deadshot, Jai Courtney as Captain Boomerang, Joel Kinnaman as Rick Flag, Hernandez as (we assume) El Diablo, and Cara Delevingne as Enchantress. Viola Davis will play Amanda Waller. Ed Harris, Jackie Earle Haley and Joe Manganiello are rumored to appear as well.
Suicide Squad is expected to start shooting this month for a release on August 5, 2016.