Apple sells a subscription with an RTC for a given number of users and an
update subscription for the same number. You receive only one software
package, regardless of the number of copies you are licensed to create. You
mount this copy on your server, so workstations can use it. Similarly, you
receive one update software package and mount it for your users.
For example, if you buy an RTC for 10 users, you also need to buy a software
update for 10 users. It doesn't matter if fewer than 10 users are active. You
can take advantage of your remaining count when you add new users.
This structure is necessary, because Apple must track A/UX copies for AT&T's
royalty reports.