<link href="https://example.com/rss.xml" rel="alternate" title="RSS feed for example.com" type="application/rss+xml"/>
<link href="https://example.com/atom.xml" rel="alternate" title="Atom feed for example.com" type="application/atom+xml"/>
[1] https://developer.mozilla.org/en-US/docs/Web/HTML/Element/li...[2] https://developer.mozilla.org/en-US/docs/Web/HTML/Element/me...
At this point, I just use CTRL+U and search "rss" and "atom", hoping to find a the corresponding <meta /> tag. It's a shame Firefox does not automatically display a feed icon anymore, it would be much better if I want to tell non technical people about RSS. Installing an extension is workable but it's also an additional step.
Most browsers have removed RSS, so now you need to either read the HTML (which sucks even if you're familiar with it) or just guess. If you want to instruct the general audience on how to get RSS feeds these days, and you don't want to link to browser extensions (because only a few mobile browsers support them), then "just add /atom.xml" seems like the most foolproof solution to me.
It too could use a mention of autodiscovery though.
"To find the RSS Feed for a website, just navigate to the website and the RSS feed for it is usually located at the domain of the website followed by /rss.xml, /rss or /atom.xml".
Recently on HN there were infos that pages provide meta links to atom. This is cleaner solution than guessing.
There was also Firefox extension 'want my rss', etc etc.
This should be better explained on RSS site.