One set of two...need clarification :)

Could someone clarify what “at least one set of two on either side to secure it” means? This is for a hat on DPNs. I am familiar with one stitch marker, but a set of two on either side? I’m confused!!~from self taught beginner.

Instructions are for size S (M, L). Cast on 48 (54, 60) sts, dividing over four needles in multiples
of 2; place a marker for the start of the round with at
least one set of 2 on either side, to secure it.

Because the stitch pattern is multiples of 2sts, the pattern wants you to divide the cast on sts among 4 needles in multiples of 2. That way, you can do the k2tog with sts on the same needle.
It’s difficult to put a marker at the beginning of a dpn. It keeps sliding off! So the directions want you to place the marker [I]2sts[/I] (one set of 2sts) in from the end to hold the marker on the needle.
Maybe this pattern?

yes, that’s exactly the pattern! Must be well known! Thanks for your help!