comments

A single-line comments starts with "--" and ends at the end of the line, eg.

a = 42 -- initial value of 'a'

You can also use "block" comments by following the hyphens by brackets like this:

--[[
  Written by Nick Gammon.
  Date: 3rd June 2011
]]

To allow for nesting block comments you can add in one or more "=" symbols like this:

--[=[
  Written by Nick Gammon.
  Date: 3rd June 2011

  --[===[
    Nested comment.
  ]===]

  Not nested.
]=]