It means that if you are in Australia you can buy NZO on the ASX. The exempt bit is that they do not have to comply with all the listing rules that a firm applying for listing on the ASX in an IPO would as they are already listed here etc.
ASX Foreign Exempt Listings are entities that are listed on another securities exchange and have a secondary listing on ASX. They must comply primarily with the rules of their home exchange and are exempt from complying with most of ASX's Listing Rules.
https://www.asx.com.au/products/fore...isting%20Rules.