A compilation of the experimental p+p\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$p+p$$\\end{document} data of neutral and charged kaon production has revealed a discrepancy between the observed Ks0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^{0}_{s}$$\\end{document} yield and the the average number of produced charged kaons Ks0=(K++K-)/2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^{0}_{s}=(K^{+}+K^{-})/2$$\\end{document}. 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\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$p+p$$\\end{document} 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.