PDF documentation covering two MSI board codes, MS-7B47 and MS-7A68, revision 1.0, delivered in a 1.78 MB RAR archive. The name suggests the same design or closely related layouts are shared between both numbers. The PDF is filed as boardview material but is probably a schematic or printed layout. Expect circuit diagrams for power sequencing, VRM controllers and I/O. Technicians use it to trace rails and signals during board-level repair. Check that your board carries one of these codes and revision 1.0 first.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @BoardSchematic. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.