This is regarding highers...

I have seen a few of these threads but am yet to get my answer.

What does a university mean when they say "these results must be achieved at first sitting", does this mean 5th year or just not a repeat i.e getting a B in Higher History ,doing it again and getting an A

Does second sitting mean:

1. 6th year
2. the second time you sit highers (completely different highers from the first time) or
3. sitting four highers , getting 4 C's and sitting the exact same highers again?