Here is some info about front barricade access for Sticky & Sweet tour dates in Europe:

"You will be given a meeting point at the venue where you will go to and then you will be given access to the front barricade. Guaranteed front barricade access simply means that you have guaranteed access to the front barricade which is situated at the front of the stage. You will be near the stage. People cannot access the front barricade without a hot ticket."

Source: Madonna Tribe