[retina]

Originally Posted by Uncwilly

Wiktionary disagrees with you dear sir:
https://en.wiktionary.org/wiki/crosspost

Hehe, well then Wiktionary disagrees with you also.

Originally Posted by Uncwilly

Crossposting is in reference to posting the same content across multiple subfora.

Originally Posted by Wiktionary

An electronic message posted to multiple newsgroups simultaneously.

And Wikipedia says this:

Crossposting is the act of posting the same message to multiple information channels; forums, mailing lists, or newsgroups. This is distinct from multiposting, which is the posting of separate identical messages, individually, to each channel, (a forum, a newsgroup, an email list, or topic area).

So I guess you actually meant multiposting.