Ascending and descending a steep snow slope safely requires the use of an ice axe and different footwork techniques that have been developed over the past century, such as the "French technique" and "German technique". Teams of climbers may choose to attach everyone together with a rope, to form a rope team. The team may then secure themselves by attaching the rope to anchors. These anchors are sometimes unreliable, and include snow stakes or pickets, deadman devices called flukes, or buried equipment or rocks. Bollards, which are simply carved out of consolidated snow or ice, also sometimes serve as anchors. Alternatively, a roped team may choose not to use anchors; instead all members of the team will prepare to use their ice axes to self-arrest in the event should a team member fall.