Cube-it 16.3 User Documentation
The Split Curve command will split a curve without the need for geometry creation (unlike imprinting).
To split a curve
Split Curve <id> [location on curve options] [Merge] [Preview]
To split a curve, simply specify a location or a location on curve (see location specification). Using the Preview keyword will draw the splitting location on the curve. The Merge keyword will merge any topology that contains the newly created vertex.