We are sending icds compressed AFP (Advanced Function Presentation) Datastream
from our Z/OS System to mobile Linux Systems via lpd protocol. On the Linux
Systems based on rhel5-client-rc1 we have configured a server argument for
cups-lpd in /etc/xinetd.d/cups-lpd:

# default: off
# description: Allow applications using the legacy lpd protocol to communicate
with CUPS
service printer
{
        disable = no
        socket_type = stream
        protocol = tcp
        wait = no
        user = lp
        server = /usr/lib/cups/daemon/cups-lpd
        server_args = -o document-format=application/icds
}

We did this to enforce that everything that comes in via lpd has to pass our
cups filter icds2ps. Therefore we have two files /etc/cups/icds.types:

application/icds

and /etc/cups/icds.convs

application/icds        application/postscript  0       icds2ps

We have commented out application/octet-stream in /etc/cups/mime* :
/etc/cups/mime.convs:#application/octet-stream  application/vnd.cups-raw       
0       -
/etc/cups/mime.types:#application/octet-stream

The Problem now is, that the server_args argument seems to be ignored and
everything is passed to cups as application/octet-stream and not as
application/icds.