Instrument Flight Rules (IFR) 2 : When weather conditions are below the minimums prescribed for visual meteorological conditions, pilots must fly in accordance with IFR
Ilan Kelman (ed.), Vulnerability and Resilience Definitions and References, Version 2, 2007. http://www.islandvulnerability.org/docs/vulnres.pd f, (Vulnr and Resilience - Brit) {524}