Gage R&R (gagerr)

There are many variants of gagerr. Does anyone know which one MATLAB implements? judging by the data, it maybe the one used in the Auto Industry Action Group of the American Society for Quality (AIAG's), but it also seems to spit out two values on for % Variance, and one for %Study Var, which includes a 5.15 factor. The earlier matches data published in other commonly used spreadsheets in industry, the later seems a bit inflated, which is Donald Wheeler's argument.

Any of you stats jockey's up to answer this? I am acoustician who is back in manfucaturing (my first career) of audio stuff, so its been 20 years since I have looked at a GRR data set.