The extraction of the strangeness form factors from parity violating elastic
electron-proton scattering is sensitive to the electromagnetic form factors at
low Q^2. We provide parameterizations for the form factors and uncertainties,
including the effects of two-photon exchange corrections to the extracted EM
form factors. We study effect of the correlations between different form
factors, in particular as they impact the parity violating asymmetry and the
extraction of the strangeness form factors. We provide a prescription to
extract the strangeness form factors from the asymmetry that provides an
excellent approximation of the full two-photon correction. The corrected form
factors are also appropriate as input for other low-Q analyses, although the
effects of correlations and two-photon exchange corrections may be different.Comment: 9 pages, 4 figures, to be submitted to Phys. Rev.