Use the MSAF as you wish because so many other ppl abuse the system like this.
Opinions on the MSAF system I find are usually split by age. Those in upper years used to have to prove MSAFs by handing in doctor's notes / obituaries etc or we would get a zero. The school system in general was a lot more strict even a few years ago.
Now zeros in high schools are virtually impossible to get due to "No-Zero policies" being adopted all over Canada. The insane inflation in highschool has almost destroyed the whole point of grades in the first place. Some schools in Canada are even removing the (already really low bar) honor roll.
http://shine.yahoo.com/parenting/can...153500429.html
Point is the younger years grew up in a far more lenient system where marks are given if a parent basically complains and there are no real consequences. And its getting worse...maybe there will be 5 free MSAFs per semester in 5 years...