  Bohr's complementarity principle has long been a fundamental concept in
quantum mechanics, positing that, within a given experimental setup, a quantum
system (or quanton) can exhibit either its wave-like character, denoted as $W$,
or its particle-like character, denoted as $P$, but not both simultaneously.
Modern interpretations of Bohr's complementarity principle acknowledge the
coexistence of these aspects in the same experiment while introducing the
constraint $W + P \le \alpha$. Notably, estimations of $W$ or $P$ frequently
rely on indirect retrodiction methods, a practice that has led to the claim of
the violation of Bohr's complementarity principle. By taking a different route,
recent advancements demonstrate that complementarity relations can be
rigorously derived from the axioms of quantum mechanics under specific quantum
state preparation conditions. To reconcile these observations and eliminate
potential paradoxes or violations, we propose an updated formulation of Bohr's
complementarity principle, which is stated as follows: \textit{For a given
quantum state preparation $\rho_t$ at a specific instant of time $t$, the wave
and particle behaviors of a quanton are constrained by a complementarity
relation $W(\rho_t) + P(\rho_t) \le \alpha(d)$, which is derived directly from
the axioms of quantum mechanics.}
