They're deprecated expressions, so they don't appear in the list, but projects created with them can keep using them.
The names are weird, IIRC they were only added for debugging purposes! The name refers to the algorithm used for moving along a path. It's implemented as a sort of "chase the rabbit" algorithm, i.e. the object chases a point a short distance ahead on the path.
TBH since they're not listed the name you choose probably doesn't matter much.