I frequently call out waste yarn in my patterns. This is just a substitute for a stitch holder. Personally, I don't use stitch holders.
magic Archives - Jill Wolcott Knits
Waste Yarn in Place of Stitch Holders - Jill Wolcott Knits
tutorial
Stitch Markers, GSR Markers, and Pin Markers - Jill Wolcott Knits
Returning Stitches to Needle - Jill Wolcott Knits
The Wool 'n Tart
Knitting Tutorial - How to use 'waste yarn' for holding live
Using Scrap Yarn Instead of Stitch Holders - PurlsAndPixels
Knitting Eucalan Delicate Wash