"for" can probably be removed without harm.

Remove "that".

"Something like" is vague. Like it how?

up in <filename>pkg-plist</filename>. When

the port is upgraded, it will not be necessary to edit dozens (or in some

<filename>pkg-plist</filename>.</para>

<para>If files are installed conditionally on the options

Break sentence after "enough".

s/need to/must/

s/the files carefully/files that have been carefully/

This is a little vague. @sample does all the work, all the porter has to do is use it. Maybe this is clearer with the sentence split into two:

Instead, install sample files with a <filename><replaceable>filename</replaceable>.sample</filename> extension. The <literal>@sample</literal> macro automates this. For each sample file, add a line to <filename>pkg-plist</filename>:</para>

Would be nice to explain that if the actual file is not present, the sample file will be wirtten to it. Also, on uninstall, config files that have been edited by the user will not be deleted, or overwritten by the sample file when reinstalled.

Break sentence after "used".

s/need to be/must/

Break sentence at "if":

"...is created. If they are not created by the port code, create them in the Makefile:"

"Then" is not needed.