At 249 KB this PDF is the largest in the group and covers the 2SA1618, indexed as a schematic but in practice a transistor reference. Japanese JIS numbering assigns the 2SA prefix to PNP devices built for high-frequency use. The name carries no further detail about maker or variant. On the bench, a sheet like this tells you which leg is collector, base and emitter, what voltage and current the part tolerates, and which characteristics a substitute must match before you solder it in.
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.