8.5 Several National Planning Guidelines (NPPGs) provide policy guidance that impinge directly or indirectly on City Centre functions, e.g. NPPG 2: Business and Industry, NPPG 3: Land for Housing, NPPG 8: Town Centres and Retailing, NPPG 17: Transport and Planning and NPPG 18: Planning and the Historic Environment. Planning Advice Note 59: Improving Town Centres (PAN 59) provides advice on good practice in promoting the economic and environmental health of the City Centre. The Joint Structure Plan acknowledges the City Centre as the strategic business and retail centre for the West of Scotland. The Glasgow Alliance recognises that the strategic functions of the City Centre have a crucial role to play in strengthening the economic development of the City.