The use of organic nitro compounds, such as nitrobenzene sulfonic acids, in chemical mechanical polishing compositions is disclosed. This allows for the key top to be prevented from abutting the membrane sheet when the key top is displaced by the user from the raised position to the lowered position. The door assembly includes an actuator configured to drive a rod upwardly. In certain embodiments, removal may be performed at mass-transport limited conditions with less etchant available inside the feature than near its opening. Generic objects are created and used to represent business listings upon which the user may perform queries.