7 spaces makes sense, it's 3 for everything belonging to the same point on you list plus 4 for the code, see experiments on
https://gist.github.com/0xf10e/91f021b82a2bc4586b235e8f56c31f92
(Yeah, "github-flavored" markdown, but it's a common dialect these days)

I still prefer three backticks, but I come from trac-wiki syntax via ReStructuredText to markdown and using single backticks for inline monospace but
{{{
Code here
}}}
in track still annoys me.

I understand the additional value semantic markup has but in many cases it's nice but not necessary. 

-- sysadmin who never broke out into HTML in rst or markdown &hellip;