Guitar tabs

have been using guitar tabs for over 3 years now but i always seem to stumble across a symbol i don't understand is there any kind of chart of lesson even that can show me some more advanced symbols of guitar tabs?

Should be easy enough to find on google.. but there is a link on this page too..

http://www.guitartricks.com/contribute/main.php#

Before making this thred, try make a search or somthing... see what you can find first. Tab is like riding a bike, once you've got it, you've got it!