Direct Numerical Simulations (DNSs) are one of the most powerful tools for studying turbulent flows. Even if the Reynolds numbers achievable with DNS are lower than those obtained with experimental means, there is a clear advantage since the entire velocity field is known, and any desired quantity can be evaluated. This also includes computation of derivatives of all relevant terms. One such derivative provides the indicator function, which may depend on mesh spacing and distribution, and the convergence of computation. The indicator function is a cornerstone to understanding inner and outer interactions in wall-bounded flows, and the description of the overlap region between them. We find dependence of the indicator function on the mesh distributions we examined, raising questions about the classical mesh and convergence requirements for DNS.