PDF specification for the PC1602LRU-CSO-K LCD module, rated by its 1602 designation as a 16x2 character display, with CSO-K as the variant suffix. Normally the document details pin functions, supply and LCD drive ranges, backlight voltage and current, data timing and dimensions. When a two-line display on a device misbehaves, it helps confirm what each pin should carry and whether a replacement will fit. Since suffixes alter options, check the module label matches this code.
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 @acodis_lcd_datasheets_EDID. 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.