Radio Frequency I Dentification.
Id = identification
The id is one of three components of Freud's model of the psyche. The other two being the ego and the super-ego.
"The id is responsible for our basic drives such as food, water, sex, and basic impulses. It is amoral and selfish, ruled by the pleasure–pain principle; it is without a sense of time, completely illogical, primarily sexual, infantile in its emotional development, and is not able to take "no" for an answer."
I think the "RFI" stands for Radio Frequency Identification. Although I'm not sure what the "D" stands for.