Ann: RMP: Alaska Update - Rig Contract Executed, page-5

Hi Henry -
Probably because the ASX rule is that the term Price Sensitive is only meant to possibly cause some impact on the Share price of the Company that makes the obligatory Announcement. So again, it is my guess that RMP's Announcement is only copied to the ASX by any or all of the other listed Companies choosing to do so, so as to just inform their shareholders, because such company/ies have some financial tie-in - with RMP - on any involvement.
Maybe there's a threshold above which such company/ies believe that there could be some price-sensitivity effect on their shareholders' holdings dependent on such companies' percentage interest.
More simply put, as an example :
If RMP as "operator" or "lessor" or whatever makes an Announcement on any matter which it has a 60% interest, and 1 other company has the 40% balance then that 1 other company - if not obliged to do so by the ASX may choose to "Copy" RMP's Ann as to be an Ann of their own & thus likely to state in their Ann that (in their opinion) it is "Price Sensitive".
However if the %ages were correspondingly 90% RMP & 10% the other Company, then the term "Price Sensitive" - in that company's ann - would not be mentioned. All IMO of course. Guata.