The distinction between legal and administrative documents or letters, that have been used since the beginning of assyriological studies, may help understand archival documents taken separately. However, analysing archives as a whole by (re)constructing files and dossiers is the only way to make sense with documents of different natures, as they were sorted, filed, and kept by those who produced them. After a general presentation of the Old Babylonian archival documentation, this paper investigates the function and motivation of family archives and archival documents, introducing another typological distinction : among the large mass of sealed documents, which record the responsibility of persons regarding authority, whether legal or administrative, we should distinguish between documents of limited validity, recording temporary arrangements between persons, and documents of unlimited validity establishing permanent status of persons and properties, which compose the core of Old Babylonian family archives. A third class of archival texts, without any sealings, served other purposes in the archives, recording the memory of domestic bookkeeping or of archival activities as such.
