  Enfant terrible of charmonium spectroscopy, the resonance $X(3872)$,
generated a stream of interpretations and ushered in a new exotic $XYZ$
spectroscopy. In th meantime, many (if not all) characteristics of $X(3872)$
are rather ambiguous. We construct spectra of decays of the resonance $X(3872)$
with good analytical and unitary properties which allows to define the
branching ratio of the $X(3872) \to D^{*0}\bar D^0 + c.c.$ decay studying only
one more decay, for example, the $X(3872)\to\pi^+\pi^- J/\psi(1S)$ decay. We
next define the range of values of the coupling constant of the $X(3872)$
resonance with the $D^{*0}\bar D^0$ system. Finally, we show that our spectra
are effective means of selection of models for the resonance $X(3872)$.
