You can insert comments into the source file. A line starting with the keyword REM or starting with the character ' (apostrophe) is treated as comment line.
REM This is a simple program that prints the words "HELLO" and "WORD" REM to the screen PRINT "HELLO WORLD"
Or you can write it
' This is a simple program that prints the words "HELLO" and "WORLD" ' to the screen PRINT "HELLO WORLD"
However you can not use comments after commands, and therefore you can not write:
PRINT "HELLO WORD" 'This comment is invalid in ScriptBasic
PRINT "HELLO WORD" REM This comment is invalid in ScriptBasic
Note that the comment lines are tokenized and are "removed" from the source file after the lexical analyzer is done. Why is this important? Because multi-line strings may span more than one line. In this case the whole string that starts on a line being part of a comment will become comment. This way you can easily create multi-line comments that are quite useful for program documentation. For example:
' """ FILE: test.sb AUTHOR: Peter Verhas DATE: August 20, 2002 CONTENTS: This is a program that contains nothing else but a multi-line Comment. """