The structure only has one level above the SA2 level of the ASGS main structure. Parts of a State or Territory (S/T) not in an SUA are combined to form a 'Not in any significant urban area' region. The SUA structure does not aggregate to S/T, as SUAs may cross a S/T boundary. The SUAs and the individual 'Not in any significant urban area' regions cover the whole of Australia without gaps or overlaps.
From the Mesh Block level the complete list of spatial units in this structure are:
Statistical Areas Level 1 (SA1)
For more information regarding the MBs, SA1s, and SA2s, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas, July 2011
(cat. no. 1270.0.55.001).