In project databases, the way 4D allocates unique user and group ID numbers differs from the way 4D does it in binary databases. In binary mode, the user and group IDs depends on their creator (Designer, Adminstrator, or affiliated Group Owner) and the sequence of creation. In project mode, user and group IDs are dynamically allocated at database startup, except for Designer (ID=1) and Administrator (ID=2). Therefore, every time that you restart the project database, if you were to check user ID by calling GET USER LIST, for example, you could potentially see that the user IDs are different from the last time the database was started.

Below is a comparison of the user and user IDs of the same database, binary (left) vs. project (right) mode. New users were created sequentially by Designer. User IDs were obtained using GET USER LIST.