FCGetDiracGammaScheme[] shows the currently used scheme for handling Dirac matrices in D dimensions.
Overview, FCSetDiracGammaScheme, DiracTrace.
FCSetDiracGammaScheme["BMHV"]
FCGetDiracGammaScheme[]
% // FullForm\text{BMHV}
\text{BMHV}
\text{BMHV}
FCSetDiracGammaScheme["NDR"]
FCGetDiracGammaScheme[]
% // FullForm\text{NDR}
\text{NDR}
\text{NDR}