Little confused over policy WRT /usr/X11R6/bin

[Gordon Sadler <gbsadler1@ispchannel.com>]

The best I was able to answer this question myself via searching the
archives was bug# 53762 proposed by Branden Robinson, debian-x
maintainer.

Should packages that contain binaries that run under the X-window
system install those binaries into /usr/X11R6/bin?

policy 3.2.1.0 states:

_Packages using the X Window System should abide by the FHS standard
whenever possible_; they should install binaries, libraries, manual
pages, and other files in FHS-mandated locations wherever possible.
This means that files must not be installed into `/usr/X11R6/bin/',
`/usr/X11R6/lib/', or `/usr/X11R6/man/' unless this is necessary for
the package to operate properly.

The last phrase, 'unless this is necessary...' seems to be operative.
Other than scouring the source for hard coded paths, is there a way to
tell if a package 'needs' to be in /usr/X11R6/... ?

FWIW the following is produced here:
dpkg -S /usr/X11R6/bin/* |cut -f1 -d: |sort |uniq

groff
tetex-bin
xbase-clients
xcoral
xfstt
xloadimage
xserver-common
xserver-xfree86
xutils

This is a current Sid/unstable system as of today.

Thanks
Gordon Sadler