  A black hole may carry quantum numbers that are {\it not} associated with
massless gauge fields, contrary to the spirit of the ``no-hair'' theorems. We
describe in detail two different types of black hole hair that decay
exponentially at long range. The first type is associated with discrete gauge
charge and the screening is due to the Higgs mechanism. The second type is
associated with color magnetic charge, and the screening is due to color
confinement. In both cases, we perform semi-classical calculations of the
effect of the hair on local observables outside the horizon, and on black hole
thermodynamics. These effects are generated by virtual cosmic strings, or
virtual electric flux tubes, that sweep around the event horizon. The effects
of discrete gauge charge are non-perturbative in $\hbar$, but the effects of
color magnetic charge become $\hbar$-independent in a suitable limit. We
present an alternative treatment of discrete gauge charge using dual variables,
and examine the possibility of black hole hair associated with discrete {\it
global} symmetry. We draw the distinction between {\it primary} hair, which
endows a black hole with new quantum numbers, and {\it secondary} hair, which
does not, and we point out some varieties of secondary hair that occur in the
standard model of particle physics.
