I think if the local and remote instances are federated - for posts submitted to remote communities that have subscribers from the local instance - posts to the local instance can be annotated with cross-posted to:
links, whenever the local instance is aware of other federated posts that have a matching URL in other OP posts.
A single OP can manually cross post to other communities using the cross-post
button next to the title of a post, although that will auto populate the body text of the new post with quoted text from the original, as well as an embedded hyperlink to the original.
So coss-posts can be both auto detected by Lemmy, or manually created by OP(s).
My phone keyboard spelling aside, when the acronym was first coined, correct, but it seems to have sence devolved into more of a colloquialism for large scale tech related corporations, outliving the precise corporate restructuring that once comprised the old acronym. At least that's what I've experienced in my workplaces, as well as the comments here:
Was there a equivalent house hold colloquialism for IBM, HP, Xerox, Bell System, etc. back in the day?