Ann: Trading Halt, page-104

that is correct, a general NDA is the basis. on certain markets you can apply to waive the need to disclose anything while the negotiations are ongoing, since any premature disclosure could jeopardize the talks. not fully familiar with all the rules of the ASX yet.
the more transparent you are with the authorities, the less problems you can potentially face later...

depending on the strategy of management, the release of the info prior to final negotiations can put the company in a stronger position during the talks. other players could possibly also consider offering a partnership / deal based on the positive news, leading to more options for management.

lots of variables here...great place to be for management. they have the goods the market wants!