This document is a guide for drug treatment agencies, state and territory health departments and other people involved in collecting and transmitting data for the 2010–11 Alcohol and Other Drug Treatment Services National Minimum Data Set (AODTS–NMDS). It contains definitions of the data elements in the collection, and guidelines about collecting and transmitting the data in 2010–11. This document is one of a series of similar documents that provide information to assist participants in each year of the collection.