Comments (Scripting)
From Legacy Roblox Wiki
Introduction
This tutorial covers how to include comments in your script(s).
Single-line comments
A comment starts anywhere with a double hyphen (--) and runs until the end of the line:
Example: -- This is an example of a comment
Comments do not appear in the output window. They are mostly to help the programmer understand what a section of code is for in long, complicated scripts.
Block comments
Lua also offers block comments, which start with the first double brackets and run until the corresponding double brackets:
Example: --[[ This is an example of a block comment. --]]
Notice how this comment is on more than one line. In the first example, it is limited to one line.