Short instructions on how to mod the Mod version 1.1
1. with mphp MyAdmin or on the commandline, go to your pun DB and enter
INSERT INTO PREFIXconfig values('o_invitation_message','---------------')
Make sure to replace PREFIX with your prefix...
2. Open include/mod_invitation.php and go to line 29.
Replace there
$mtext = $form['invitation_text'] . "\n".$lang_invitation['Forum Link'].$act_link;
with
$mtext = $form['invitation_text'] . "\n".$lang_invitation['Forum Link'] . "\n" . $act_link . "\n" . $pun_config['o_invitation_message'];
3. Open admin_options.php and go to line 642.
After
<th scope="row">Rules</th>
<td>
<textarea name="form[rules_message]" rows="10" cols="55"><?php echo pun_htmlspecialchars($pun_config['o_rules_message']) ?></textarea>
<span>Here you can enter any rules or other information that the user must review and accept when registering. If you enabled rules above you have to enter something here, otherwise it will be disabled. This text will not be parsed like regular posts and thus may contain HTML.</span>
</td>
</tr>
, add
<!-- MOD INVITATION -->
<tr>
<th scope="row">Invitation Message</th>
<td>
<textarea name="form[invitation_message]" rows="10" cols="55"><?php echo pun_htmlspecialchars($pun_config['o_invitation_message']) ?></textarea>
<span>Here you can enter a message that users will get along with their invitation.<br />
It will be added to the text that the inviter writes</span>
</td>
</tr>
<!-- //MOD INVITATION -->
For those who installed version 1.1. this should do the trick.
All others should either replace the files and revise the readme.txt of the new version - or do it totally from scratch 
The German PunBB Site:
PunBB-forum.de
