Banter and General Comments, page-769

I was reading that announcement.

That's great news for Kidman and supports the high demand that downstream is seeing ahead by establishing agreements with a company that won't have production coming online for quite some time. (Still with the minister isn't it?)

Since you brought it up, can you please give me a hand understanding this part of the KDR announcement.

"The parties have agreed to enter into a definitive supply agreement by 30 June 2019. If a definitive supply agreement is not executed by that date
either party will have the option to terminate the Heads of Agreement based on pre-agreed
conditions."

What do they mean by Definitive Supply Agreement?