Symbol 1640 from ISO 7000Title/Meaning/Referent: Technical manual; manual for service
Function/description: To identify the location where the handbook is stored or to identify information that relates to the servicing instructions for the equipment. To indicate that the service manual or handbook should be considered when servicing the device close to where the symbol is placed.
https://www.iso.org/obp/ui#iso:grs:7000:1640
Vectorization:  IngenieroLoco