How to represent multiple files in a forum post?

[Martin Nowak]

On Wednesday, 14 February 2018 at 18:33:23 UTC, Jonathan Marler 
wrote:
> @timotheecour and I came up with a solution to a common problem:
>
> How to represent multiple files in a forum post?

Oh, I thought it already was a standard, but 
[.har](https://en.wikipedia.org/wiki/.har) is JSON based and very 
different, so the name is already taken.

Have you done some proper research for existing standards?
There is a 50 year old technique to use ASCII file separators 
(https://stackoverflow.com/a/18782271/2371032). Sure we can find 
some existing ones.
We recently wondered how gcc/llvm test codegen, at least in gcc 
or gdb I've seen a custom test case format.