This article on the usefulness of a general codification of administrative law forms the closing contribution of a NALL-special. In this special, various authors have reflected on the successfulness of a broad codification process in 1998, which introduced rules on the notification of decisions, policy rules, subsidies, enforcement and supervision of administrative authorities in the Dutch General Administrative Law Act (GALA). The editors asked the contributors whether the objectives of the rules introduced were met and how the rules turned out to function in practice. In this overarching article, the NALL-editors reflect on the general lessons to be learned for the GALA-legislator. In these lessons they also take into consideration the initiatives for a law of administrative procedure of the European Union.