The Expanded Floor Pivots is introduced in the book "Secrets of a Pivot Boss: Revealing Proven Methods for Profiting in the Market" by Franklin Ochoa. He added four new levels: S4, R4, BC and TC. There are many great ideas in the book, such using these levels, following trend, time price opportunity and much more. (Thanks to tonyjab for pushing me to read this book)
The definition/formula of the levels defined in the book: r1 = 2 * pivot - Low r2 = pivot + (High - Low) r3 = r1 + (High - Low) r4 = r3 + (r2 - r1)