Appropriate way to label axes of graphs

Prof. Brian Fiedler of the University of Oklahoma recently published an article in Physics Education calling for a change in direction in teaching dimensionless ratios in physics. As he advocates,

The tick marks [on an axis of a graph] are pure numbers. Labels with a solidus such as R/µm are orthodox notation for what the numbers represent. Labels such as R (µm) are understood by us not to be consistent with standard mathematical notation, R is not multiplying µm. Rather, (µm) is a parenthetical remark, shadowing our informality when we say ‘is in microns’.

Fiedler, B. H., 2010: How do we really compute with units? Phys. Educ., 45(2), 167–172.

Thanks to Evgeni Fedorovich for pointing out this article to me.