Tagged architecture
In computer science, a tagged architecture is a type of computer architecture where every word of memory constitutes a tagged union, being divided into a number of bits of data, and a tag section that describes the type of the data: how it is to be interpreted, and, if it is a reference, the type of the object that it points to. == Precursors == Some early systems use tagging of data in memory but do not have all of the characteristics now considered to be part of tagged architectures.