Licensing Question

We are about to buy informix version 5 and have licensing questions. What constitutes a user? At a previous employer we ran SCO and version 4.1 of informix. We had less that 30 people, but with background processes and multiple login screens, we had the Informix Shared Memory Paramater Max # of Users set to 85. Any less than this would get errors. If we get a 32 user license, can the Max # of Users be set to more than 32? Do you get a to many users error? Is it based on the number of sqlturbo processes running? I would really appreciate some help. Thank you very much. -Trevor trevor@jurist.com is the best place to mail me.