  Some QSOs show an abrupt, strong rise in polarization near rest wavelength
750 A. If this arises in the atmosphere of an accretion disk around a
supermassive black hole, it may have diagnostic value. In PG 1222+228, the
polarization rise occurs at the wavelength of a sharp drop in flux. We examine
and reject interpretations of this feature involving a high velocity outflow.
The observations agree with a model involving several intervening Lyman limit
systems, two of which happen to coincide with the Lyman continuum polarization
rise. After correction for the Lyman limit absorption, the continuum shortward
of 912 A is consistent with a typical power-law slope, alpha = -1.8. This
violates the apparent pattern for the Lyman limit polarization rises to occur
only in ``candidate Lyman edge QSOs''. The corrected, polarized flux rises
strongly at the wavelength of the polarization rise, resembling the case of PG
1630+377. The rise in polarized flux places especially stringent requirements
on models.
