How to differentiate Capacitance (Italized C) and Coloumbs (regular C) on paper I am doing a question on capacitance and coulombs. I got the answer correct, but I was wondering how a physicist, when doing the calculation on paper, would differentiate a C and C?
 A: I will omit the fact that capacitance is measured in Farads, as I see a more general use to the question. For the sake of this answer I will answer as if we are symbolically manipulating capacitance and use the variable $C$.

I usually don't have this issue with capacitance, but when I want to make explicit that I'm using a capital letter that is non italicized what I'll do is put a line under it. For instance I would write $C$ for capacitance and $\underline{C}$ for coulombs. 
Like I said this is probably overkill for capacitance and coulombs, but I think it's useful in a broader context.
Downfalls: If you're writing fast it can get kind of messy if your capital letter appears in the numerator like $\frac{\underline{C}}{C}$ and wind up looking awkward, so I only do this if I know it's not going to be an issue. 
2$^{nd}$ solution:If it is unavoidable and the algebra will get nasty I will write my capital letters as "double struck". So for instance $\mathbb{C}$ would be Coulombs in this case, and I just close my eyes and hope that I don't need to mention the complex numbers.
