- Your variable name can start with $, _ or a Unicode Letter (Lu, Ll, Lt, Lm, Lo, Nl).
- For the rest of the name of the variable you can use $, _, Unicode Letter or Unicode Number (Nd).
If you don't feel in a comfort zone when using Unicode extensively, there are other thing you can abuse. One of the other thing you can abuse is the way some character are displayed. The best example of this is the character underscore. In most text editor, it's very hard to know how much of them there is when you place them one after the other. Are _____ and ______ the same variable name ?