When a process writes to a FIFO (see sec. 4.3 for a definition of FIFO) and no process has that FIFO open for reading, the write fails with an EPIPE error condition. In addition, a SIGPIPE signal is sent to the process trying to write to indicate that a write was attempted on a FIFO with no readers.
In a network environment, it is possible that processes using a remote FIFO on a server may not all be located on the same client. In this case, since the server coordinates access to the FIFO, the server notifies the client of the EPIPE error condition and of the necessity of sending the SIGPIPE signal to the process. Thus, this issue is a protocol issue, not an issue requiring a modification to the semantics associated with SIGPIPE. The semantics of SIGPIPE on the client can be maintained as long as the client is notified by the server that the EPIPE error condition has occurred.