  The scattering by the inner accretion disk of X-ray radiation generated near
the surface of a spinning neutron star in a low-mass X-ray binary (LMXB) has
observable effects on the waveforms of millisecond X-ray flux oscillations
produced e.g. during type-I bursts or in the millisecond pulsar SAX
J1808.4--3658. We study these effects in the framework of a simplified model in
which there is a single emitting spot on the stellar surface, which is visible
both directly and in X-rays scattered from the disk. The main signature of
scattering from a thin disk is that the pulse of scattered flux leads (if the
star rotates in the same sense as the disk) or lags (in the contrary case) the
primary pulse of direct emission by a quarter of a spin cycle. This is caused
by Doppler boosting of radiation in the sub-relativistic Keplerian flow. The
disk-scattered flux is revealed better in energy-resolved waveforms and the
phase dependence of the polarized flux component. The phenomenon discussed
permits direct testing of the presence of standard thin disks near the neutron
stars in LMXBs and should be observable with future X-ray timing experiments
having a few times better sensitivity than RXTE and also with sensitive X-ray
polarimeters.
