  Hawking's radiance, even as computed without account of backreaction, departs
from blackbody form due to the mode dependence of the barrier penetration
factor. Thus the radiation is not the maximal entropy radiation for given
energy. By comparing estimates of the actual entropy emission rate with the
maximal entropy rate for the given power, and using standard ideas from
communication theory, we set an upper bound on the permitted information
outflow rate. This is several times the rates of black hole entropy decrease or
radiation entropy production. Thus, if subtle quantum effects not heretofore
accounted for code information in the radiance, the information that was
thought to be irreparably lost down the black hole may gradually leak back out
from the black hole environs over the full duration of the hole's evaporation.
