The system was developed for research purposes by the American biochemist Alexander Shulgin, and published with co-authors Ann Shulgin and Peyton Jacob, III, in a 1986 issue of the journal Methods and Findings in Experimental and Clinical Pharmacology.
It was later described in the Shulgins' popular 1991 book PIHKAL: A Chemical Love Story.
An identification of the chemical being ingested, a dosage, and a descriptive narrative including the ratings themselves used to describe various moments in time.
The rating itself gives a comparable value relating to the subjective intensity of the experience, including auditory, visual, emotional, mental, physical and other sensory effects.
The narrative may include various Shulgin ratings, noting the time to achieve various levels, for instance: (with 22 mg) A slow onset.