String Variables
The String Variable selection box lists all the string variables contained in the currently opened script. Use this selection box to paste a String variable into an expression.
A String variable has a constant (unchanging) value and the string concatenation operator + implicitly creates a new String variable. A String variable consists of the set of Unicode characters from “\u0000” to “\uffff” inclusive.
The default value of a String variable is the empty string, that is, "".