This report provides an improved technical basis for reporting indicators of injury occurrence in Australia. The current set of National Health Priority Areas (NHPA) injury indicators has been documented thoroughly to enable them to be reported without ambiguity concerning which cases should be included, calculation methods, or other technical considerations. In addition, the precise purposes of the indicators have been reviewed, and a set of revisions to the technical specification has been proposed, in order to improve the capacity of the indicators to serve these purposes. The technically revised specification is designed to provide more valid monitoring of trends in the population incidence of serious injury in Australia.