How do I specify spline 2nd derivative constraints but not 1st derivative constraints when using spapi?

According to the spapi documentation, I can specify equality constraints on derivatives when using spapi by repeating elements in the X vector and placing the constraint values at the same position int he Y vector. For example,

spapi(knots, [0 1 1 1 2], [0 1 0 0 2]) would have:

f(0) = 0

f(1) = 1

D^1 f(1) = 0

D^2 f(1) = 0

f(2) = 2

Suppose I wanted to specify a constraint for D^2 f(1) but not for D^1 f(1). How would I change the X and Y vectors?

Thanks!