This tutorial is showing a tuck stitch T2 (T is for tuck, 2 is for two floats).
Work T3, T4, etc tuck stitches the same way. The only difference will be is how many floats you tuck in.
Noa Triangular Scarf pattern is available on Ravelry.com For this tutorial, CO 23 sts. Work a few rows in reverse Stockinette while keeping first 3 sts and last 3 sts in I-cord. End with a knit row. Video begins on RS row (purl side) and shows how to slip stitches and perform T2.