UICollectionViewFlowLayout - Spacing

When going between storyboards/Interface Builder and code - there are some inconsistencies in naming. For example in UICollectionViewFlowLayout there are 2 variables for spacing: minimumLineSpacing and minimumInteritemSpacing. In Interface Builder we see:

Not really intutive but Min Spacing For Cells -> minimumInteritemSpacing and Min Spacing For Lines -> minimumLineSpacing