weird documentation of -C option

[wm75]

the manual says this about -C:

Cost for a non-canonical GT-AG splicing (effective with --splice) [0]

but what is a "non-canonical GT-AG splicing"? Is it meant to say non-canonical (non-GT-AG) splicing instead?

Another note/question: (effective with --splice) should be added also to the -u option description?