Thread tags observation

[BRotondi]

Hello

I'm using thread tags to categorize threads. So I want to log tag changes.

As a first step I tried to send me an email after each change. But i failted to create a plugin with something like

vbmail($vbulletin->options['webmasteremail'], "Tags Changed", 
"User: " . $vbulletin->userinfo['userid'] . "\r\n"
. "Forum: " . $threadinfo['forumid']) . "\r\n"
. "Thread: " . $threadinfo['threadid']) . "\r\n"
. "Title: " . $threadinfo['title']) . "\r\n"
. "------------------------------------" . "\r\n"
. "New tags:  " . $$$ . "\r\n"
. "Old tags: " .  $$$
, true);

Problem: Which hook and which file changes are necessary to make this run? It's quite complicated ...

Is there some code / addon or similar I could use? Or any idea?

Thanks for any help!

Bruno