# Language Reference - Directives

Pre-processor directives are a means of telling a script (or compiler) to behave in a special way. They begin with a hash (#) and are placed at the top of a script.

Below is a list of alphabetized pre-processor directives supported in AutoIt.

Directive | Description
--- | ---
#comments... | Specify that an entire section of script should be commented out
#include | Includes a file in the current script.
#include-once | Specifies that the current file may only be included once.
#NoTrayIcon | Indicates that the AutoIt tray icon will not be shown when the script starts.
#OnAutoItStartRegister | Registers a function to be called when AutoIt starts.
#pragma | Changes how the script is compiled.
#RequireAdmin | Specifies that the current script requires full administrator rights to run.