if filters get run ONCE when several jobs come in.
of filters get run for each job that's printed.

I'm pretty sure.

Filters are executed as daemon.daemon (usually).

Quoting dbonnafo@algol.dyndns.org (dbonnafo@algol.dyndns.org):
> hi,
> 
> my printcap is as follow :
> 
> # APS1_BEGIN:printer1
> # - don't delete start label for apsfilter printer1
> # - no other printer defines between BEGIN and END LABEL
> lp|PS;r=300x300;q=medium;c=gray;p=a4;m=auto:\
>     :lp=:\
>     :rm=perseus:\
>     :rp=brother:\
>     :if=/usr/pkg/etc/apsfilter/basedir/bin/apsfilter:\
>     :sd=/var/spool/lpd/lp:\
>     :lf=/var/spool/lpd/lp/log:\
>     :af=/var/spool/lpd/lp/acct:\
>     :mx#0:\
>     :sh:
> # APS1_END - don't delete this