First, remove "Disallow: /forum/" from your robots.txt file.
Next, go to the PhpDig admin panel and copy down the "update sites" values for your site.
Then, enter each FAQ-type URL that you want to index, one per line, in the PhpDig textbox like so:
Code:
http://www.john-howe.com/forum/phpbb/viewtopic.php?t=XXXX
http://www.john-howe.com/forum/phpbb/viewtopic.php?t=YYYY
http://www.john-howe.com/forum/phpbb/viewtopic.php?t=ZZZZ
Now, set the radio button to no, search depth to zero, links per to zero, and click the dig button.
Once PhpDig is done, go to "update sites" and edit the values back to their original settings.
Remember to add "Disallow: /forum/" back to your robots.txt file.
PhpDig currently does not understand robots.txt "allow" lines.
Also, read
this documentation for further information.