I didn't see anything about the robots.txt approach, but this support page discusses the meta tag method.

https://support.google.com/webmasters/answer/6229325?hl=en

I was specifically asking because I’d never heard of a robots.txt solution for blocking snippets. None of the responses have included that information.

Why don't you try being a little kinder, especially when you don't have all the facts?

It's not as though web design like knowledge of meta tags and robots.txt is the sum total of everything to know about computers. Maybe they've built their own 8-bitter, or are a motherboard PCB designer? I'd argue that'd put them firmly in the 'computer guru' class. But we don't know, so it's probably better to say nothing at all.

Hey, thanks. I've done all those things but tbh the name predates all that. I was an op in a tech support irc channel in the 90s/00s and that was the name I'd picked at the time (I was not comfortable with tying my ID to myself IRL but perhaps even moreso, I was also very sensitive about being pretty much the only minority on all the user groups and mailing lists I frequented. The "guru" half of the moniker was somewhat an homage to being a minority, although I'm not Indian).

I messaged the HN mods many years ago (either pg or dang, can't remember) when things had changed and I had decided to just use my real name online but was told that it would not be possible to change it for posterity purposes.