Really good point. That always annoys me with most formulas. I have to dig back several paragraphs (with no scope/indexing tool) to figure out what the individual variables mean.

And a lot of papers do not even bother to explain some variable but just assume the reader already knows it. One of the earlier commenters made this mistake very prominently enthusing over Maxwell's equations.

Yes of course the formula looks better shorter when you already know what it means. But that completely misses the point that it was written down to explain it to someone who doesn't already know what it means. If you already do you're the wrong target audience.

Longer variable names would help. Or for online paper just have a tooltip that opens the paragraph that explains what the variable mans when you hover over it would also help a lot.

Or maybe some color coding to easily find it (there was a recent link here recent explaining FFT which used this trick very successfully)

But I guess most Mathematicians don't bother because they only write for a small circle of colleagues anyways.