A pharmaceutical storage and retrieval system and a method of storing and retrieving pharmaceutical containers from the system. Computer-executable instructions receive a request to implement a change in configuration data. By virtue of the use of the new GUID, new changes made after restoration will not be confused with any changes made by the server after the backup and before the restoration, which are identified by the old GUID of the server, thereby ensuring convergence of the servers’ data through replication. Amplitude stops or combinations of phase and amplitude filtering patterns can also be used to capture N different sets of intensity data in a conjugate diffraction plane. The invention further relates to a brake pad and a clutch facing comprising the coated fibres.