What do the @@ +#,# -#,# @@ lines in MC source patches mean?

[CatRabbit499]

I have noticed that in the Forge source on github there are what look like some kind of annotation on MC source patches that takes the form of @@ -#,# +#,# @@ where '#' is a number, but I can't find anything on stackoverflow or general google searching about it. Does anyone know what this is and how it is used?

Example: link

Edited September 19, 2018 by CatRabbit499
title clarification

[jabelar]

I believe those come from "unified diff" format. See https://www.gnu.org/software/diffutils/manual/html_node/Detailed-Unified.html#Detailed-Unified

[CatRabbit499]

So, would the [ - / + ] signs then mean so and so lines [ before / after ] this line then?

[jabelar]

It tells you what has been added and what has been deleted relative to the original file that is being patched.