  General formulae for the spin-spin correlation parameters $C_{i,j}$ and
spin-transfer coefficients $K_i^j$ are derived for the reaction $N N\to Y
\Theta^+$ at the threshold for an arbitrary spin of the pentaquark $\Theta^+$.
It is shown that a measurement of the sign of $C_{y,y}$ or an observation of
the non-zero polarization transfer from the nucleon to the hyperon $Y$ allow
one to determine the P-parity of the $\Theta^+$ unambiguously and independently
on the spin of the $\Theta^+$.
  Measurement of these spin observables in the both $pp$- and $pn$- channels of
this reaction determines also the isospin of the $\Theta^+$.
