When adding a span & versine annotation between two structures, it is placed by default in the middle of the two structures and automatically rotated to align with the track centre (shown in the picture below as red lines) to help with layout legibility.
This means for complex track arrangements, each versine will rotate respectively to the track it’s associated with.
When moving a span & versine annotation, its rotation will not change regardless of where you move it, as demonstrated below.
