Reference Cinema 4D Basic Features Create Menu Spline
Function available in CINEMA 4D Prime, Visualize, Broadcast, Studio & BodyPaint 3D

Spline

Basic Coord. Object

Spline

This command creates an empty spline object. Like the Polygon object, it is recognizable on screen only by its origin and axes.

This object can serve as a base for the construction of splines (e.g., using the Spline Pen). However, a spline is usually created automatically as long as an existing spline is not already selectec.