I added my courses and it says ok... but in MUGSI, in the column showing C/L/T, I can't choose the core for some of my courses. Does this mean they are full?!?!?

For some courses, I was able to choose CLT but for others I couldn't at all!!! But I was able to add my courses and it says "passed".

At this time in the registration you cannot chose core for most courses. For the ones that you can usually only let you chose core if its a choice between day and night.