  There is an apparent discrepancy between the results of the charged kaon
multiplicities off the deuteron target from HERMES and COMPASS experiments. In
this article we point out that this discrepancy cannot be explained by
different $Q^2$ values. Furthermore we examine the empirical parametrization of
the fragmentation functions, DSS2017 carefully and find that the agreement
between the theoretical estimate and the HERMES data is less satisfactory as
claimed.
