  The amount of non-stoichiometric oxygen in La_{2-x}Sr_xCoO_{4+y} is
calculated from Sr doping, x, and the measured stripe incommensurability 2delta
for x = 1/4 and x = 1/3 based on a linear or square-root dependence of delta(x,
y). The results favor the square-root dependence and indicate that the range of
excess oxygen extends to x < 0.4 instead of to x < 0.3 as previously thought,
coinciding with the low-temperature orthorhombic (LTO) phase.
