This is prompted by
which asks why s is used as the letter for position. Here are some more examples.
Differentiating between mass number (A) and activity (A) in a nomenclature/glossary
Is there any mathematical proof of Newton law of universal gravitation?
How do you pronounce $\vec{A} \cdot \vec{B}$ and $\vec{A} \times \vec{B}$?
What's a good mnemonic for intensive and extensive properties?
(Feel free to edit in more examples. Posts not prone to the auto-deletion script are preferred.)
Are these questions on topic? They're not really about physical concepts, but they are about matters that are fairly specific to physics.