Hybrid Server
Smaller sites with limited network bandwidth may operate "sucking" or cache servers. These perform the same reader server role as conventional news servers, but themselves act as newsreaders to exchange articles with other reader servers. Hybrid servers allow greater flexibility in that received groups can be adjusted without manual intervention by remote server operators. They may also be the only available means to obtain articles from remote servers that do not offer conventional feeding.
Because hybrid servers usually use the posting function to send news, article headers are reformatted by the posting function and tracing information can be lost. Also, the delayed sucking process can result in excess activity on the remote reader servers. For these reasons, the use of hybrid servers is often discouraged or disallowed without prior agreement.
Read more about this topic: News Server