(We have no relation to OP and were also surprised to see this posted under Show HN)

Very sorry as my intention was not to claim the work. I completely ignored the posting rule because I did not know. A friend of mine sent me the link and I found Radio Garden so amazing that I wanted to share it to this community. I really meant no other intentions except sharing it widely for the greater good. Again apologies to the author studiopuckey and everyone else who felt offended.

What's "Show HN" etiquette here? Is submitting something two years old cool, or is it only supposed to be for new things or posted once?

As others pointed out, the issue is that it needs to be the submitter's own work. We've taken "Show HN" out of the title above.

https://news.ycombinator.com/showhn.html

Yeah, I'd say it's cool as long as you're not spamming it. 2 years is a long time and likely out of the memory of most. But, this is just my personal opinion. For example, I've never seen this site and it's pretty cool. Happy it was posted.

Reposting the same Show HN with a different user ID is strange though. It's supposed to be personal work

This post might be some sneaky marketing for whatever it is OP is promoting in its profile.

This is the second random Show HN post in three days under this profile.

It is supposed to be for your own work that you want feedback on. Using the "Show HN" tag for a "normal" submission is a potential hack or cheat to try to get a bit more visibility and increase the odds of getting traction. When used that way, it's deemed a misuse of the tag.