I use a four-part description of how to use a Jack Plane as a basis for comparison when working out how to explain how to use software tools. When I write a user manual, I need to be sure that if the software publisher redesigns the interface that it will have only the most minimal effect on the descriptions of any functionalities.
Supposing that the manufacturer of the jack pane decides to make a version where the rear handle ('tote') is shaped like a saw handle (poignée à jour) instead of the classic swan-neck? I'll update the section that describes the parts, and possibly the assembly. I'd expect to have to add a short explanation of why the manufacturer has chosen to deviate from a well-established pattern.
I would not expect to have to change any explanation of how to use the plane.