The ECMAScript standard indicates that JS variable names can be pretty much any Unicode character. I have tested this out in this fiddle with the variable __$. This appears to pose no problems to all my desktop browsers (IE down to IE 8 - the last I tested), iOS6 on Safari and Chrome, my own ancient Android smartphone. However, I want to look before I leap - is there any probability that a recent handheld device (I do not care about supporting the ark) might burp when it sees a variable such as
var __$,ǰ
etc?