It looks like you’d increase in the next stitch and then knit 4. If the entire row is a repeat of these directions, then it could be that you’re working in stockinette from this point on?
Or it could just be an error.
How many stitches do you have on the needle and how many are you supposed to end up with?
It looks to me like it should read to knit in the first stitch. I know I’m a little old fashioned. I tend to write 1st for first, 2nd for second, 3rd for third, 4th for fourth, etc. I never thought about it, but that’s probably the popular way they wrote things out 50 years ago when I was a kid. That’s what I think this is, 1st(first) stitch.
The entire row reads:
17th Row: Increase (inc) in [U]1st st[/U], K 4, * sl 1, K 1, p.s.s.o., y o, K 1, y o, K 2 tog, K 5, repeat from * across row. (underline is mine)
So, as FOLiPJ’s said it’s "increase in the first st…"
Those directions repeat in the following alternate rows as you increase in that first st.
When a pattern says to increase IN a stitch, that indicates doing a kfb. So don’t simply knit 1 first, kfb then k4. If you’d rather do a m1 inc though, then you would k1, m1, k4.