Usually it is onbvious whether a variable accepts a single value or a range. All variables that accept a range obviously accept a single value too. However, there are some variables where a single value is meaningful, but a range can be useful as well. Business Functions has two ways in which variables can effecetively be operated in two modes: singular or plural. The two ways are by Auto Multi variables (described in detail elsewhere see Auto Multi Functions) and optional plural variables, which are suffixed with an '_s' (eg ØIdxRegularity_sØ).

The '_s' really means '(s)', like 'VariableValue(s)', meaining the variable can be specified singular or plural. In fact, as far as the function is concerned, the variable is a plural range, and it will work out how you mean to use it be looking at how many elements it contains. So plural variables are really ranges that you can simply specify a single value. They are used in situations where, for simple use of a function, you might want to set just one value for a variable that you want used in all instances where the function uses that variable, but that when, in other situations of more advanced usage, you want to specify a range so that different values of the variable are used, say at different times, depending on what the function says in its documentation.

The difference between plural '_s' variables and variables in Auto Multi Functions variables is that variables in Auto Multi Functions are for when the whole function will be re-run with the multiple values specified in its Auto Multi variables. Plural variables use the different values with a single calculation of the function