For the 2SD1011, this 42.1 KB PDF carries an _E tag in the name with no stated meaning. It appears among schematics, yet the JIS designation 2SD signals an NPN transistor of the low-frequency class, making it a component reference. Technicians open it to verify pinout ahead of desoldering, to check absolute maximum ratings and to compare hFE classes. When a direct part is unavailable, the ratings here are the baseline any substitute must meet in the same footprint.
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.