20.24 chart:interpolation - definitions of b-spline and cubic-spine seem insufficient

Read in full:

"b-spline - B-Splines. The chart:spline-order attribute specifies the order of the polynomials used for calculation. 20.48 The chart:spline-resolution attribute specifies the number of interpolated points between two data points. 20.49

cubic-spline - Cubic Splines. The chart:spline-resolution attribute specifies the number of interpolated points between two data points. 20.49"

Ok as far as it goes but doesn't tell me anything about b-spline and cubic-spine.

In fact, simply repeats information already present elsewhere.

Suggest deleting the definitions as written and supplying definitions for these attributes.

There is an implied statement of polynomials somewhere but it isn't clear where from this entry.