Excerpts from the Live in Chicago 2017 2CD set liner notes:
"Q: Where is this Formation in the series of King Crimson incarnations?
A: This sonic report is presented by King Crimson Formation 8.3.
There are four Definitive Formations of King Crimson:
The First Definitive Formation: 1969.
The Second Definitive Formation: 1974 at the last live performance in NYC and the recording of Red.
The Third Definitive Formation: 1981.
The present formation, returning to the US in Autumn 2017, is King Crimson v. 9.1, the Fourth Definitive Formation.
Q: What is a Definitive Formation?
A: Nothing is quite the same afterwards.
Friday 25th, August, 2017
Bredonborough, Middle England"