User blog comment:Scorcher007/About Cofinality, sipmly/@comment-35470197-20190722064020/@comment-35470197-20190722090721

I agree that we usually need the knowledge of cofinality in order to understand OCFs, because many of them are based on regular cardinals. However, Buchholz's OCF is based on small cardinals instead of larger regular cardinals, we do not actually need the knowledge of the cofinality, if we have the knowledge of cardinality. Therefore Buchholz's OCF (or the restricted one up to \(\psi_0(\Omega_2)\)) is one of a good starting point.