Help Required to Explain Knitting Instruction


I’m having trouble understanding the knitting instruction for one particular round of knitting of a beanie on a pair of 4mm circular needles.

The instruction reads:

Rnd 15: p around
Rnd 16: k around
Rnd 17: [working through first purl st of Rnd 15 and next st on needle, k these together] repeat around.

Please help decode the instruction for round 17?

It might be making a tuck or ridge but it would be easier to tell for sure if you can post the pattern name or a link to it. We can’t post entire patterns here but the few lines, a name or a link are ok.
Here’s a video for the stitch that I thinking of:

Hello salmonmc,

Thanks very much for your reply and the suggested youtube video. I was able
to create the small ridge effect on my project to look like the picture of
the project. Cheers!

Best regards