A
korah may be placed diagonally across the opening of a
mavoi-alleyway. However, carrying is only permitted up until the edge of the
korah. It follows, that one will be able to carry further if one is carrying on the side of the
mavoi that has the long side of the
korah placed over it.
A
korah is only valid if the opening of the
mavoi is ten
amos or less. The
poskim disagree if, a
korah which is placed diagonally and stretches for a distance of more than ten
amos, is still valid.
[
שו"ע שסג, ל, משנ"ב קכו, שעה"צ קיד, וביה"ל ד"ה יכול; ביאורים ומוספים דרשו, 127]