Decay indices

[Paterson, Adrian Mark]

Hi all

A friend has just received some reviewer's comments about a phylogenetic 
manuscript.  One of the reviewer's indicated that the use of decay indices 
(Bremer indices?) would give an estimate on the robustness of nodes within the 
tree.  What are decay indices and how are they calculated?  Any help would be 
appreciated.

Thanks
Adrian
Lincoln University
New Zealand