  The relations between masses and decay constants of variety of meson
resonances in the energy range 0--3 GeV are verified from the string-like,
linear mass spectrum for vector, axial-vector, scalar and pseudoscalar mesons
with a universal slope. The way to match the universality with the Operator
Product Expansion (OPE) is proposed. The necessity of small deviations from
linearity in parameterization of the meson mass spectrum and their decay
constants is proven from matching to OPE.
