The cover schedule is a phenomenon at Abu Dhabi Men's College that doesn't exist for the math department. The number of math teachers is small enough that one teacher has the list and if someone is sick, the other teachers get calls and/or emails to teach the classes.
The English department has a different system. Even though this is my fourth semester teaching at ADMC, this is the first semester dealing with the system. Apparently what happens is we get an email at 5:02 pm after most people have left saying that the list is up and people need to find three class periods during the week that they can agree to teach if someone is sick and needs someone to teach at that time. Then at 7:02am the next day before most people are there, we get another email saying thanks for the fast response and that most of the slots are taken. At 7:50am, the teachers who are unaware of the system (like me) read the email and put their names down for whatever is left.
While this sounds like complaining, I got the times I probably would have taken even if I signed up at 5:03pm last night. Two interesting bits of information, though. First, I was told not to write my name in pencil because someone who wanted that time would probably erase my name and write their own. Second, as I was walking away after having written my name, I overheard a coworker who also had arrived late saying, "Oh good, someone wrote my name for me." That's right, it's not just the students who act in their own self interests.