A number of problems that middle-division students seem to have with physics content are actually problems with notation:

• conventions for spherical coordinates

The following three papers are from the Vector Calculus Bridge Project Instructor's Guide. Put a link here. Wikify these sections. Add to the Bridge book and put a link.

• vectors
• what sort of a "beast" is it?
• dimensions

• using primes on variables and confusion with derivatives: Primes
• primes for spatial derivatives vs dots for time derivatives: Dots
• what our students had to say about changes in notation