OBD
From Just Solve the File Format Problem
Microsoft Binder was a companion application with Office 95, 97, and 2000 which allowed multiple objects into a single file.[1][2]
Office XP and 2003 also supported the format, but only through an UNBIND.EXE application to save out the individual objects/components.[3]
File Information
OBD files are in the OLE2 Microsoft Compound File format. OBT are template files.
All Binder files have a file "Binder" within the container, but in Office 97 and 2000, an additional "HdrFtr" file was added.
OBZ files are template files but with included macros.