Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filedfiledCritical
Publication of BE678934ApublicationCriticalpatent/BE678934A/fr
Enveloppes reutilisables pour la reponse, a element de mise en place de la patte de fermeture pour la reexpedition, et procede de preparation de ces enveloppes pour l'expedition