So, interesting notion, probably some of you already know: boosts ("re-toots") can be deleted by clicking on the 🔄 symbol. However, if the boost has crossed the border to another instance, it cannot be deleted from there!
You can only delete boosts from your own instance. They will still appear to your followers who follow you from different instances!
Worth knowing: Private toots will NOT federate, as long as you don't mention an account on another instance. Also a warning will be displayed if will federate to another instance.
IF it federates to another instance, ALL who follow both you and the mentiones account can see the toot.
That, however, does NOT mean your toot is no longer private. It will only *federate* with a mentioned instance. Think of it as a copy on that instance.
@TQ Well, it also doesn't mean it IS private. The other instance can be customized to ignore privacy, or it can be GNU Social and simply not support Mastodon privacy, receiving it publicly like any other status.