"From Ballroom Competition Figures Marcus Hilton."
Serendipidy's description matches that in Geoffrey Hearn's book 'A Technique of Advanced Standard Ballroom Figures' which I would expect as he produced the Marcus Hilton video.
Guy Howard's book has a different version where most of the turn is made at the beginning, and therefore needs a slight difference in rise. Some may refer to this figure as a hairpin.
1: LF fwd facing LOD, HT, rise e/o 1, turn up to 1/2 L
2: RF fwd, small step, R side leading, towards alignment of 3, T, Up
3: LF fwd in CBMP, facing DC ALOD or ALOD, TH, lower e/o 3 (heel does not lower until next step is taken).
He also notes that following a reverse or slip pivot, step 1 will be taken in CBMP.