lemmy isn’t designed to do that, but mastodon is. For example if you paste the perma-link for your comment lemmus.org/comment/791388 into the search bar of your Mastodon account on Theres.life you’d find the same content at theres.life/…/110834025709111907
maybe, maybe not. Particularly if your account is followed by anyone with a platform that doesn’t support DELETE from remote servers, like like earlier versions of Diaspora and GNU Social. and yoru delete command might not work such as if the remote server is down when the delete request is sent. Once you choose delete most platforms send a request to every server that it knows of to delete the same, if it doesn’t get a response within a certain amount of time it will request it again, and after so many failures it stops trying. The server could later come back up and it never know that the item was deleted.
I’m not sure aware off hand of any servers that make it easy for admins to turn off the ability to delete, but its Free Software so anyone could download the source code edit it as they see fit, like removing the delete function, compile it and run it on their own server.
Its a really great reminder that we all should assume anything that has ever been posted on the internet will exist forever. So don’t post stuff that is going to come back and haunt you.
It is its own community that happens to be federated with Lemmy and Mastodon. You can toggle federation on and off, and when off, you only see kbin's material. Otherwise it functionally acts like another lemmy instance, with a different interface and features missing from base lemmy.
There is also a microblog attached to it that connects with Mastodon in the same way. Each community has its own microblog that acts as a hashtag when on Mastodon.
I know, but having separate accounts within the interfaces of each site can be helpful. If I have a Mastodon account, I know exactly how my posts are going to look and act on Mastodon. Same goes with Lemmy and Kbin.
I also have access to features on one service I wouldn't have on others. Some posts are easier to view and access from a different site or instance. Kbin doesn't have any mobile apps yet, so I use my Lemmy account when I want to access fed on mobile.
Lastly, sometimes I'm just in the mood to use one site over the other. If I'm in the mood for more Twittery content I go to Mastodon. If I'm in a more Reddit mood, I go on Lemmy. If I want to do both at the same time, I use Kbin.