Definitions of "cross posting" on the Web:
* Crossposting is the act of posting the same message to multiple forums, mailing lists, or newsgroups. This is distinct from multiposting, which involves posting multiple identical messages, each to a single forum, newsgroup, or topic area.
* Posting an article to more than one Usenet newsgroup.
* Posting the same articles or comments across several different Internet Forums. This is similar in protocol as spam.
There are other meanings too. I believe there are many different things that could be considered cross posting, such as:
1. Starting multiple threads with the same content in different areas of the forum.
2. Starting a new thread that is basically just a link to another thread in a different area of the forum.
3. Starting a new thread that is basically just a link to another thread in a different forum. (Such as the UPS horror story recently posted)
4. Linking back to other threads. (Such as when an OP posts a new thread asking about what sax to buy. And then a seasoned SOTW member posts a reply with a link to one of 10,000 other threads where the same question has been well answered.)
5. Reply with quotes from other threads.
6. Simultaneous replies that are either the same or where the first one renders the second irreverent.
And there are a lot more.