Portuguese knotted stem stitch

This stitch is not actually a knotted stitch. However it visually gives the impression of a knotted version of stem stitch and it creates a textured, rope-like line when stitched with a thick twisted thread.
Method
Start by working a stem stitch. After bringing up a needle halfway, slide the needle under the first stitch. Do not go through the fabric.
Pull the thread tight to wrap the stem stitch, and then slide the needle under the first stitch again. The second wrap sits just below the first wrap.
Pull the thread to tighten the wraps, and then start another stem stitch.
Keep the loop to the right of the needle and come up in the same hole at the end of the first stem stitch.
Slide the needle under both first and second stem stitch.
Work another wrap so that it lies in place below the first wrap. Make sure not to pick up the fabric when whipping.
Repeat the procedures and continue stitching upwards.

Embroidery Techniques
Related Stitches
References
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Kate Haxell, The Stitch Bible (2012) , p.102
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Jennifer Campbell, Ann-Marie Bakewell, Guide to Embroidery Stitches (2004) , p.49
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Erica Wilson, Erica Wilson’s Embroidery Book (1975) , p.37