  A compilation of the experimental p+p data of neutral and charged kaon
production has revealed a discrepancy between the observed $K^{0}_{s}$ yield
and the average number of produced charged kaons $K^{0}_{s}=(K^{+}+K^{-})/2$.
This widespread relation holds only for a colliding system that is an uniform
population w.r. to the isospin (i.e. that consists of an equal number of all
members of a given isospin multiplet). This is not the case for p+p collisions
therefore one should not expect that it will describe the data accurately. A
much better agreement is obtained with a model based on the quark structure of
the participating hadrons.
