The present invention provides a tent having a retractable roof. The system and method utilizes a lanyard for drawing the residual limb into a receiving portion of the prosthetic limb and for helping to maintain attachment of the prosthetic limb to the residual limb. In embodiments in which a purchaser’s authorization is checked with respect to a determined threshold value, a record of the authorization check can be stored and can subsequently be retrieved to verify that an authorization check for the encounter was carried out using the determined threshold value. 5 m, and on the surface thereof at least 1104 projections standing at least 20 nm high and at most 1103 projections standing at least 70 nm high per mm2 measured by an atomic force microscope.