Persona 4/ZZZZZ.BIN

The ZZZZZ.BIN file found in the PS2 version of Persona 4 appears to be a copy of the BTL.CVM from Persona 3's original JP release.

Purpose
Many PS2 games contain "dummy" files that intentionally fill the remaining free disk space. This is done in hopes of improving load times by pushing used data to the outer edge of the disk. However, in the case of emulation, this file is useless for improving load times and can be deleted without any negative impact, as the executable doesn't reference any of the files in the BIN. For more instances of Persona 3 leftovers in Persona 4, check the TCRF page.