The following directives are supported during preprocessing:
| Directive | Description | 
|---|---|
| #Const | Defines a symbol | 
| #If | Evaluates a condition, if the condition is true, the statement following the condition is kept otherwise it is ignored | 
| #Else | If the previous #If test fails, source code following the #Else directive will be included | 
| #Else If | Used with the #if directive, if the previous #If test fails, #Else If includes or exclude source code, depending on the resulting value of its own expression or identifier | 
| #End If | Closes the #If conditional block of code |