# Reionization optical depth from Planck 2018 large-scale E-mode
# polarization (the "lowE"/SimAll likelihood).
# Planck Collaboration (2020), A&A 641, A6, arXiv:1807.06209, Table 1
# (TT,TE,EE+lowE baseline).
#
# plik_lite covers only l >= 30, where tau enters solely through the
# exp(-2 tau) damping of the spectra and is therefore degenerate with
# the primordial amplitude A_s. Adding this prior is what breaks that
# degeneracy -- it is the standard companion to a high-l-only CMB fit,
# not an optional extra.
#
# [value] [sigma]   tau_reio
0.0544 0.0073
