# Curved and Flat Indices

However the indices chapter has no mention regarding "curved" and "flat".
Are these just names or is there more to it? The Fierz transformation problem
has something like

{\mu,\nu,\rho}::Indices(curved, position=fixed).
{m,n,p,q,r,s,t,u,v}::Indices(flat, position=independent).

I don't understand the function of curved and flat

Those are just names; the full form of that first property is

 {\mu,\nu,\rho}::Indices(name=curved, position=fixed).