A summary is given of an IAEA consultants�?? meeting on �??Total Absorption Gamma-ray Spectroscopy for Decay Heat Calculations and Other Applications�?�. Participants assessed and reviewed plans and progress from 2005/06 and 2009 to identify and determine those radionuclides that merit measurement of their total absorption gamma-ray spectra (TAGS) in order to assist in the determination of the decay heat in and antineutrino spectral emissions from power reactor systems. This debate follows on from similar exercises undertaken by Subgroup 25 of the OECD-NEA Working Party on International Evaluation Cooperation of the Nuclear Science Committee in 2005/06 and a previous IAEA consultants�?? meeting in 2009. Various highly-relevant TAGS studies were undertaken from 2006/07 onwards based on the recommendations of WPEC-25. A further re-assessment of the request list formulated in 2005/06 and adjusted in 2009 is merited at this time. Debate focused on fission- and fusion-based decay-heat needs and the monitoring of antineutrino spectra to assist in non-invasive safeguards. Agreement was reached in re-defining and extending fission-reactor decay-heat and antineutrino spectral requirements for TAGS measurements as a tabulated list.