I'm debugging a particularly thorny bit of printer misbehavior, and to do it I need to learn more about the conventions for specifying printer filters in /etc/printcap. Because of the problem I'm dealing with, it's easier for me to work with lprold rather than lprng (installing lprng doesn't solve the problem but makes the debugging more difficult). The man page for printcap is not at all informative about printer filters -- for example, it mentions nothing about the convention of using a pipe as a printer filter. The termcap man page is no better and the Linux Printing HOWTO isn't helpful on that subject either. I know I've seen some better documentation on printer filters, but now I can't seem to find it. Any pointers? Also, any pointers on the permissions and ownerships of spool files that Berkeley lpd, i.e, lprold, expects? Paul