CAAB - Codes for Australian Aquatic Biota - is an 8-digit coding system for fishes and other aquatic organisms in the Australian region maintained originally by CSIRO Division of Marine Research and now CSIRO NCMI. CAAB can be used to obtain a taxon code for any species or species group on the CAAB list for use in data storage, or to obtain the current scientific name or other information for any CAAB taxon code. For groups where coverage of the Australian fauna is complete, it can also be used to generate lists of currently recognised Australian marine taxa in any genus, family or selected higher-level category. Taxon codes are useful for data storage where it is desirable to maintain the collected data (e.g. catch or survey data) independently from the associated name information (which is subject to revision or correction with changes in taxonomic knowledge). CAAB codes are also "meaningful" and convey information about the organism's classification down to the level of family, and so can be used for rapid sorting and filtering if desired. CAAB currently contains over 4,500 codes for fishes, 250+ codes for other marine vertebrates (reptiles, seabirds, and marine mammals), over 5,000 codes for marine invertebrates (including sponges, stony corals, echinoderms, commercially important crustaceans and molluscs, tunicates, and other taxa), and codes for Australian seagrasses and mangroves and a representative selection of Australian seaweeds and microalgae. While concentrating on the fauna and flora of the Australian Fishing Zone (AFZ) surrounding mainland Australia, some taxa from the broader Australasian region are also included, as well as species imported from other countries for sale domestically. CAAB also incorporates on-line links to further sources of taxonomic information such as the Australian Faunal Directory, the international directories FishBase, AlgaeBase, the US ITIS (Integrated Taxonomic Information System) database and the World Register of Marine Species (WoRMS). Links to WoRMS are particularly useful as any public occurrence data published to the Ocean Biodiversity Information System requires a WoRMS identifier The Fisheries Research and Development Corporation (FRDC) maintains the Australian Fish Names Standard (AS 5300) and Australian Standard for Aquatic Plant Names (AS 5301) vernacular name standards. Selected images are available per taxa. In particular the application Fishmap (https://www.marine.csiro.au/data/caab/fishmap.cfm) contains search tools for images and maps of the modelled species distribution of fish species. It is an updated version of the original Fishmap hosted by Atlas of Living Australia as it is current and contains regions in the Antarctic and Australia's offshore islands of Macquarie, Lord Howe, Heard and McDonald, Norfolk, Christmas and Cocos Keeling.