It's part of the changes made to the MyAdmin page a couple of days ago. I actually kind of like it, gives you more of an idea on what is going on with your assignment. The legend is as follows:
n.a. - not available or not applicable
... - marks still being processed
PP - Portfolio - marks only available as course results
## - marks processed but not not released
What I am not sure about is why with Cos361 the marks we already received for assignment 1 is also ##, but its probably just a bug and will be fixed.