Dollar-sign Expansion is a process that allows us to replace text in an expression, or line of script, with either the value of a variable or some other calculation.

Suppose that we have a variable with a value of 10 and we write an expression like the following:

Sum(If(Field1=$(vValue), 1, 0))

The Dollar-sign expression, $(vValue), will get expanded to its value (10) and the expression that gets executed will be as follows:

Sum(If(Field1=10, 1, 0))

We can also have a calculation inside the Dollar-sign expression like the following:

If(Year=$(=Year(Today())), LightGreen())

In this case, the function Year(Today()) will be calculated and its value replaced into the main expression in the following manner:

If(Year=2014, LightGreen())

We do have to be aware that it is the exact value of the Dollar-sign expression that is replaced into the main expression, and it becomes as if we have typed that value there. Therefore, if it is a string value rather than a numeric value...