outlook 2007 folder icons what do they all mean?

[stevep]

Is there a page that discribes what each folder icon represents? I am wanting
to know what the folder with 2 blue arrows pointing left/right is?

 

[neo [mvp outlook]]

Means that the folder is set for synchronization with the mail server.

If you see a hand under a folder, it means that it is shared.

I couldn't find anything that covered the folders in Outlook, but there is
this for items.
http://www.outlook-tips.net/howto/icons.htm