KKR PREPARES BID, page-59

http://chi-x.com.au/Portals/15/CXA_MOC_2015_brochure_v1web.pdf

HOW DOES IT WORK?
The Market on Close (MOC) order is a continuously traded fully hidden
order type available between 10:00 and 16:12. Alongside this Chi-X now offers an @ Last trading phase between 16:12 and 16:20 in which participants can also enter visible as well as hidden MOCs.
All MOC orders are unpriced and once matched reference the ASX closing price when it becomes available. Orders are matched based on time priority between 10:00 and 16:12 and during the @ Last trading phase on visibility
> time priority. If a participant has broker preferencing logic enabled, they will match against their own MOC orders as first priority.

For MOCs matched between 10:00 and 16:12 participants will receive an
initial real time execution message followed by a final message confirming the ASX closing price once it becomes available. For MOCs executed immediately following the ASX close between 16:12 and 16:20 participants will only receive one execution as the final price is known