RE:RE:When can rio start buying on the open market?A couple of extra terms listed in their presentation (Slide 4): https://westerncopperandgold.com/wp-content/uploads/2021/06/WRN_Corporate_Presentation_June2021.pdf
"Rio has the right to retain ownership". I take this to mean that if WRN issues shares, RIO can buy shares to maintain their percentage ownership.
Don't know what other conditions apply to buying shares, but it looks like the arrangement anticipates that Rio might. It states "Rio has the right to appoint one director of the Company, if Rio Tinto's ownership increases to at least 12.5%".
The purpose of this rights plan is to ensure that Rio doesn't increase its stake before a deal. If Rio were to get 19.9% ownership it would be a big impediment to a counter offer.