The property below, set in /properties/config.properties, tells the unique id of the first administrator of the application. It is used when running the ant task init-data which initilizes the database and creates the first objects.

#init.firstAdministratorId=paubry

It can be a local user (e.g. paubry) or an external user (e.g. pascal.aubry@univ-rennes1.fr).
See: 00 Users