Now... Stockinette is knit, purl - purl, knit
Reverse Stockinette is knit, purl - knit, purl

What is ribbing?

Hmm... well ...

Stockinette and reverse alternate knit and purl between rows ... knit row 1, purl row2, knit row 3, purl row 4 ...

Ribbing is alternating knit & purl within the row as well as between the rows...

Row 1 - k3, p1, k3, p1, k3, p1, k3
Row 2 - k1, p1, k3, p1, k3, p1, k3, p1, k1

This is the ribbing pattern on the sweater that I'm making now

Hmm... does that make sense? :?

That makes sense, but I was referring to kitchener stitch for ribbing, not ribbing itself.