Double prefixes Double prefixes have been used in the past, such as micromillimetres or millimicrons (now nanometres), micromicrofarads (μμF; now picofarads, pF), kilomegatonnes (now gigatonnes), hectokilometres (now 100 kilometres) and the derived adjective hectokilometric (typically used for qualifying the fuel consumption measures). These are not compatible with the SI.
Double prefixes Double prefixes have been used in the past such as micromillimetres or millimicrons (now nanometres) micromicrofarads (μμF; now picofarads pF) kilomegatonnes (now gigatonnes) hectokilometres (now 100 kilometres) and the derived adjective hectokilometric (typically used for qualifying the fuel consumption measures) These are not compatible with the SI