You should benefit from adding these to your profile environment (example
for sh/bash, adjust for tcsh as appropriate):

	PLAN9=%%PREFIX%%/plan9; export PLAN9
	PATH=$PATH:$PLAN9/bin; export PATH

You can also install a default plumbing file if you want:

	$ mkdir -p ${HOME}/lib
	$ %%PREFIX%%/plan9/plumb/initial.plumbing ${HOME}/lib/plumbing

When installing from the port (as your normal user), you can simply type
(while in the port directory) to do the same:

	make install-user

BEWARE:  This port can cause some problems if you try to install certain
software (including, but not limited to our Ports Collection):

  - Ports that require `archivers/zip' to build (e.g. `www/mozilla').  If
   `$PLAN9/bin/zip' would be found as `zip' command (via $PATH) and used,
    it could easily fail since it does not share options with "standard"
   `zip' (at least not all of them)

  - `x11/kdebase3' build can result in crash in `fish.cpp' file if you try
    to build it with $PLAN9.  We suggest you to unset PLAN9 before building
    any ports that fail with similar symptoms (or unset it for all ports
    just to be on the safe side)

  - venti/fmt* commands work only with normal files