  We undertake a detailed study of the gaugings of two-dimensional Yang-Mills
theory by its intrinsic charge conjugation 0-form and centre 1-form global
symmetries, elucidating their higher algebraic and geometric structures, as
well as the meaning of dual lower form symmetries. Our derivations of orbifold
gauge theories make use of a combination of standard continuum path integral
methods, networks of topological defects, and techniques from higher gauge
theory. We provide a unified description of higher and lower form gauge fields
for a $p$-form symmetry in the geometric setting of $p$-gerbes, and derive
reverse orbifolds by the dual $(-1)$-form symmetries. We identify those
orbifolds in which charge conjugation symmetry is spontaneously broken, and
relate the breaking to mixed anomalies involving $(-1)$-form symmetries. We
extend these considerations to gaugings by the non-invertible 1-form symmetries
of two-dimensional Yang-Mills theory by introducing a notion of generalized
$\theta$-angle.
