When cross-posting (short Crosspost even Multiposting ) refers to the simultaneous transmission of a document to multiple newsgroups or Web forums . This will reach a larger number of readers, and at the same time the discussion will be divided between different locations.
Crossposting on Usenet
In order not to split up a subsequent discussion of the contribution, it makes sense to only continue it in one of the forums. In Usenet this is possible by setting a so-called Follow-Up -To: header. In this, the author suggests a suitable newsgroup. Alternatively, the value "poster" can be used to ask to send the answers directly to the original author as an e-mail.
Excessive cross-posting is not permitted on Usenet by some users and administrators, especially advertising, but these rules are private. The Breidbart index defines a calculation rule that can be used to determine whether a cross posting is spam .
In Usenet, multi-postings are cross-postings that are not generated with the help of a list, but by multiple sending to only one newsgroup. This method is mostly rejected by some Usenet users, as it does not offer the possibility of holding the discussion in just one place and thus understanding its course. In addition, depending on the number of newsgroups, there is a significantly higher memory consumption, which adds up in many ways.
Cross posting in web forums
Similar to Usenet, multipostings are not permitted within the web forums by some users and administrators, as the threads that are created in this way have no connection to one another and the discussion is therefore conducted simultaneously and unnecessarily in different places. In forums in which multiposting is allowed, a linking of the threads is usually required.
Contrary to this, in forums crossposting is also the almost simultaneous sending of different posts by different users in one thread. This makes the content traceability difficult with the usual chronological presentation of the postings or false references can occur.