cross-trades are MOSTLY between brokers without directly accessing the ASX or Chi-X ( but they have to report them after the fact )
say i wanted to change brokers but NOT sell the existing holdings the brokers concerned would arrange an off-market transfer ( for a fee of course ) another case might be i inherited a portfolio of shares , now those shares shouldn't stay in the estate trust forever ( although some do for complicated trusts ) and i get those shares transferred to a different trading account ( they don't go through the market but do get registered as cross-trades
a DIFFERENT cross-trade is NXXT that is a trade directly between two clients of the same broker ( or platform ) Commsec uses that code but i assume other brokers might do the same , when that situation arises
don't panic but there are all sorts of details in there .. directors getting their performance bonuses , look at the market BEFORE it officially opens and see what is traded while the ASX is officially closed for trading