the Blackboard register

We've discussed various registers in the past few classes across the academic discipline, from study groups to office hours to course packs. One that we haven't looked at, though, that is unique to UNH, is the on-line Blackboard.
Professors use Blackboard to communicate with students, who in turn use it to get homework assignments and useful websites and to access their grades and other information for each of their classes. I would say that the Blackboard is a register, but I can't yet tell the specifics of it. For example, some professors use it strictly in a formal way, only giving the bare minimum amount of information that isn't already on their syllabus, and posting succinct announcements only when necessary. Other professors, however, take full advantage of this on-line communication medium; new announcements will be posted a few times a week with tidbits of suggestions and information needed for the next class and grades for all assignments are updated regularly.
Because each professor uses Blackboard to a different extent, it is hard to pinpoint the characteristics of this register. But I have noticed that announcements are usually written in the second person, directing students to do a certain task. This makes the computerized communication seem more personalized, and simply more direct.
The Blackboard is a unique register in that each professor can decide how to utilize its resources. However, the shared purpose is the same for all users: to give and receive necessary information regarding classes at UNH.