VMS Help TCPIP Services, Programming Interfaces, Sockets API, accept(), Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 s
    A socket descriptor returned by socket(), subsequently bound to
    an address with bind(), which is listening for connections after
    a listen().
 addr
    A result parameter filled in with the address of the connecting
    entity, as known to the Communications layer. The exact format of
    the structure to which the address parameter points is determined
    by the domain in which the communication is occurring. This
    version of Compaq C supports only the internet domain (AF_INET).
 addrlen
    A value/result argument. It should initially contain the size of
    the structure pointed to by addr. On return it will contain the
    actual length, in bytes, of the sockaddr structure that has been
    filled in by the Communications layer.