[Revan]

This is lush, I foresee this having a boatload of installs even if not HOTM (I always type HTML when I try to type HOTM )

Might I suggest using {1}, {2}, ... {n}, like so:
Change phrase "anti_autopm_bud_mes" to this:

Hello,

{1} has added you to his buddy-list. If you like to get friends you need to add {1} to your buddy-list, too.

[url={2}/profile.php?do=addlist&userlist=buddy&u={3}]Click here[/url] to add {1} to your buddy-list now.

The Board Admin

Change the "anti_autopm_bud_tit" to this:

{1} has just added you to his buddy list!

Change this snippet of code:

PHP Code:

$anti_autopm_bud_tit = str_replace("$1",$vbulletin->userinfo['username'],$vbphrase[anti_autopm_bud_tit]);
$pmdm->set('title', $anti_autopm_bud_tit); 
$anti_autopm_bud_mes = str_replace("$1",$vbulletin->userinfo['username'],$vbphrase[anti_autopm_bud_mes]);
$anti_autopm_bud_mes = str_replace("$2",$vbulletin->options['bburl'],$anti_autopm_bud_mes);
$anti_autopm_bud_mes = str_replace("$3",$vbulletin->userinfo['userid'],$anti_autopm_bud_mes);
$pmdm->set('message', $anti_autopm_bud_mes); 


to this:

PHP Code:

$anti_autopm_bud_tit = construct_phrase($vbphrase['anti_autopm_bud_tit'], $vbulletin->userinfo['username']);
$anti_autopm_bud_mes = construct_phrase($vbphrase['anti_autopm_bud_mes'], $vbulletin->userinfo['username'], $vbulletin->options['bburl'], $vbulletin->userinfo['userid']);
$pmdm->set('title', $anti_autopm_bud_tit);
$pmdm->set('message', $anti_autopm_bud_mes); 


Saves inventing a whole new construct_phrase() function

Again, nice work