Half linen stitch

Can someone tell me where I can find information about how to do the half linen stitch?

Thanks

Half Linen Stitch
(multiple of 2 sts + 1)
Row 1: * K1, with yarn in front slip 1 purlwise,* repeat between *, end K1
Row 2 & 4: Purl
Row 3: K1 *K1, with yarn in front slip 1 purlwise * rep between * to end, K2
Repeat Rows 1-4