Printers that reside on remote hosts should have an empty lp entry.
For example, the following /etc/printcap entry directs output to the printer named lp on the machine named ucbvax:
lp|default line printer:\ :lp=:rm=ucbvax:rp=lp:sd=/usr/spool/vaxlpd:
The rm entry is the name of the remote machine to connect to; this name must be a known hostname for a machine on the network. The rp capability indicates that the name of the remote printer is lp (you can leave it out in this case, because this is the default value). The sd entry specifies /usr/spool/vaxlpd as the spooling directory instead of the default pathname, /usr/spool/output/lpd.