Hi Carthorse!
It's in your subscriptions I take it? Anyway...
A
red envelope means the topic is 'Hot', more than 15 posts or has been viewed in excess of 150 times. A
blue envelope means the thread hasn't been updated since you last looked. A
yellow envelope means there are new posts to read and I assume a
Lock can only mean the thread has been closed. This could be the case when a Topic no longer needs any replies for a certain reason or is just for information purposes. In the latter case it may also say
Sticky, which means it stays at the top of that particular board.
The colour the thread envelope becomes is solely down to how popular the thread is, it isn't based on who the author is.
Near the bottom of your subscriptions page, here
http://www.wildaboutbritain.co.uk/fo...bscription.php, you will find a Key to the symbols.
Hope this helps!!