Select the 'Annotation New' button from the Linear Draft toolbar and follow the prompt to select the first structure to annotate.
After selecting the first structure, follow the next prompt
Once the second structure has been selected, the span & versine will be automatically calculated and input into your model.
If this selection is for a structure that covers multiple tracks (like in the example below), then all tracks span & versines will be added.
The 'Select Second Structure' prompt will remain visible until you cancel the action. You are able to continue adding span & versine values along a track length with each click on a structure adding in the values between the chosen structures.