Additional Details for arXiv:1711.09893

We here present extra details for the results published in arxiv:1711.09893 ("A general theory of linear cosmological perturbations: stability conditions, the quasistatic limit and dynamics"), that were omitted in the paper for brevity. Specifically we give results for the special vector-tensor case with $\alpha_D = 0$:

1. In the file "StabilityConditionsVTII.pdf", we give the coefficients of the mass matrix and antisymmetric kinetic-mass mixing terms required to explicitly compute the stability conditions for this model.

2. In the file "QuasistaticParametersVTII.pdf", we give the modified gravity parameters $\mu$ and $\Gamma$, which come out of the quasi-static analysis for this model.