What does hemiheterocercal mean when describing a holostean tail?

When describing the tail of a holostean fish, the term hemiheterocercal refers to a specific structural arrangement where the body lobe turns upward slightly, yet the tail fin remains externally symmetrical.1

This configuration represents a transition between the heterocercal tail—where the vertebral column extends into a larger, asymmetrical upper lobe—and the homocercal tail, which is characterized by symmetrical lobes and a vertebral column ending near the middle of the fin base.213