I have seen this feature many times and i have always asked myself which site offers data that could be used for that feature but i couldn't figure out untill now. Is it ment to be used for raidleaders and the dkp-system??

Could you please give me some examples??

I made a wow addon that shows each guildie how many loot points (essentially DKP) he/she had updated to the last time he/she logged a character in./sorted the guild dkp list, etc.

That was possible using a website, and UU's downloading feature.

a couple years ago I had made an addon which allowed the forum posts to be viewed in game, and also let people set the "EMOTD" (Extended MOTD) I called it from either in game or the website.

This was back when there was very limited space in the MOTD (still is?)