Amazon appends reference code to every search: nb_sb_noss_2

[gesman]

Every time I do any search on Amazon - the resulted URL appends "nb_sb_noss_2" ref code:

https://www.amazon.com/s?k=stainless+steel+bar&ref=nb_sb_noss_2

It seems impossible to get rid of this behavior no matter if i clear cookies or use privacy window. I also found lots of amazon product links on internet includes same ref. code as well.

Whom it belongs to?

Who is monetizing my (our) purchases?

[arkitaip]

I think that - including variants like nb_sb_noss - is the code for no referral identified but I could be wrong.