  The Bell inequalities can be violated by postselecting on the results of a
measurement of the Bell states. If information about the original state
preparation is available, we point out how the violation can be reproduced
classically by postselecting on the basis of this information. We thus propose
a variant of existing experiments that rules out such alternative explanations,
by having the preparation and the postselection at spacelike separation. Unlike
the timelike case where one can sharply distinguish Bell inequality violations
based on pre- or postselection of a Bell state, in our scenario the distinction
between these physical effects becomes foliation-dependent. We call this
'relativity of pre- and postselection'.
