The Advanced menu is a menu in the Second Life Viewer which is hidden by default. A lot of nice tips, tricks and tweaks directly or indirectly involve the use of this menu. I’ll explain a couple down later on the blog. Below you’ll find a link to the official documentation.
*Just want to know how to make this menu appear? You can enable it through the Advanced tab in Preferences or use this keyboard shortcut to activate the menu:
Ctrl + Alt + Shift + D