Help with yfwd

[lgoddard]

I am getting conflicting instructions on how to do a yarn forward.
I have done things with yo but these instructions say yfwd and when I have search this stitch, there are different people with different instructions on how to do it. Help please you wonderful knitting experts.
K4 *yfwd, K3, S1K, K2tog, psso, K3, yfwd, k1...

[Plantgoddess+]

In these instructions you would bring the yarn forward and around the needle and back to do your next stitch which is a knit. That would make it an increase stitch the same as a yo instruction.
Sometimes patterns call for a yfwd to slip a stitch and then brought back for the next knit which wraps the base of your slipped stitch.
I find following instructions exactly will make sense after.