Archive tied to the Z94 model, with the name pointing to revision 1.1 (R-1.1). At 863 KB, packed as RAR, it most likely contains a schematic, boardview or BIOS file for that revision, though the name does not say which. Unpack it with WinRAR or 7-Zip. A technician would use such material to follow power sequencing, find components and test points, or reprogram the flash chip. Check that the PCB is really revision 1.1 before trusting part values or pinouts taken from it.
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 @IT_SERVICE_WORLD. 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.