A fairly detailed 200 KB PDF for the 2SD2352, a JIS-numbered NPN transistor, where the 2SD prefix denotes NPN low-frequency parts. Though categorised as a schematic, the content should be a manufacturer datasheet with ratings tables, characteristic curves and outline drawings. It is used to confirm terminal assignment and limits when a transistor has shorted or is being cross-referenced to an equivalent. The name gives only the part number. Check that the package and marking on the board, including any suffix letter, match the document.
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.