>>>>under-skin liquid *tattoo* tag
Gee, sounds reminiscent of translucent inks....
Jacobus Lambertus Lentz, collaborated with the Nazis in 1941 to improve the existing ID cards and data processing systems.
August 17 (1941), Lentz devised a unique tamper-proof personal identification card that could not be forged. Translucent inks were employed to print key words that disappeared under a quartz lamp. The stamp franking was acetone-soluble. Photos of the individual were affixed front and back through a window transparently sealed and adhered with permanennt glue. A fingerprint of the person's right index finger was then impressed upon one of the photos so it always displayed through a small window. The individual's signature on watermarked paper completed the document, which included personal details.
Having created an ID Card, Lentz then anticipated the occupying Nazis demands for censuses and lists of Jews and non-Jewish slave labourers (categorised by skills and education), which were used for the mass arrests and deportations, through his IBM Hollerith punched card analyses.