Within customer premises, the importance of the cabling infrastructure is similar to that of other fundamental building utilities such as heating, lighting and mains power. As with other utilities, interruptions to service can have a serious impact. Poor quality of service due to lack of design foresight, use of inappropriate components, incorrect installation, poor administration or inadequate support can threaten an organisation's effectiveness. Historically, the cabling within premises comprised both application specific and multipurpose networks. The original edition of this standard enabled a controlled migration to generic cabling and the reduction in the use of application-specific cabling. This second edition of ISO/IEC 11801 has been developed to reflect the increased demands and opportunities which have arisen since - and are partly the result of - publication of the first edition in 1995. The contents of the corrigendas of September 2002 and December 2002 have been included in this copy.