Passthrough print is the process of having a UNIX (or similar) host program print on the printer attached to your terminal (or PC running terminal emulation). Its advantages are:
=> It prints where the user is, without requiring complicated procedures to equate printers with users.
=> It works over direct serial, modem, multiplexor, TCP/IP, etc.
=> It is immediate.
This document covers implementation of passthrough print on a UNIX/Linux host system, where this feature is not already enabled.
It worked for me and it may be helpful to someone out there :)