You select a command, and one of the elements looks like this:
That means that this element must identify one of the following:
When the element retains the default label expression, or the element is blank, or the element contains a ScanEngine Explorer variable (one of those listed on the Variable Viewer panel), the right-click selection of available variables can be produced again to permit easy reselection. Otherwise, the list of variables cannot be recalled by right-click. Why? Because, while an expression may be simply a reference to a variable, an expression can be composed of any combination of variables, functions, literals, or mathematical operators. If the element is not composed of a basic variable (or the default expression label) the program presumes an expression is being composed, and variables within the expression must be manually typed out. Be sure to remember to suffix message content objects with Object. and datafile fields with Datafile..
Expression evaluation is performed left to right, not by operator priority. Be sure to not leave expressions ambiguous ... define grouping as you wish to see them evaluated using parentheses.
Once you've replaced the Expression legend, the cell will forever remain the color associated with a Expression as a reminder that this element of the command must be an expression.
Mathematical operators +, -, /, or * can be used in expressions as long as both sides of the operator appear to be numeric. If either side of a -, /, or * operator does not appear to be numeric, it will be labeled a run-time error and script execution halted. If either side of a + operator does not appear to be numeric, then it will be executed as text-concatenate.
If you want to include a space, '\', or any control characters within any text literal, you must enclose the text between quotes and use standard escape sequences (\r, \n, \t, \f, \\, etc).