Covering the 1SS387, this 75.1 KB PDF is listed as a schematic but is best understood as a component datasheet. The 1SS numbering is the Japanese designation for small-signal diodes, and the filename adds no model, brand or revision. Inside you should find maximum ratings, electrical characteristics and the package and marking details. These are useful when a diode on a logic board is suspected shorted and needs exact identification or a substitute. Check orientation and package before you replace 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 @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.