  In a $\phi$ factory, neutral kaons are produced in Einstein-Podolsky-Rosen
(EPR) states, furthermore, a $K_S$ is tagged if its entangled partner is
detected as $K_L$, and vice versa. Here we point out that upon its detection as
$K_L$, one of the EPR-entangled particles is projected into one of the
orthogonal basis states, consequently the other particle should be projected to
the state orthogonal to $K_L$, denoted as $K_{\perp L}$, rather than $K_S$,
because $K_S$ is not orthogonal to $K_L$. Therefore the semileptonic charge
asymmetry of what was previously regarded as $K_S$ is really that of $K_{\perp
L}$. Based on this re-tagging, we modify the experimentally determined values
of several parameters, including the one describing the violation of $\Delta S
= \Delta Q$ rule, the one describing CPT violation for $\Delta S = \Delta Q$
transitions, and the time-like CPT- and Lorentz-violating coefficient for the
two valence quarks in a kaon.
