Dark-Emitting Diode (that is, a burned-out LED). Compare SED, LER, write-only memory. In the early 1970s both Signetics and Texas instruments released DED spec sheets as AFJs (suggested uses included "as a power-off indicator"). [Jargon File]

In addition suitable contents:
[ = ] [ AFJ ] [ am ] [ an ] [ ar ] [ arc ] [ arg ] [ as ] [ at ] [ b ] [ bo ] [ bot ] [ C ] [ ca ] [ cat ] [ ch ] [ cl ] [ D ] [ de ] [ du ] [ E ] [ ec ] [ ed ] [ ee ] [ ER ] [ er ] [ es ] [ et ] [ fi ] [ file ] [ ge ] [ gn ] [ h ] [ hat ] [ hr ] [ id ] [ il ] [ in ] [ inc ] [ include ] [ instrument ] [ io ] [ is ] [ it ] [ J ] [ Jargon File ] [ LED ] [ LER ] [ Lex ] [ lu ] [ ly ] [ memory ] [ mo ] [ mod ] [ module ] [ mp ] [ na ] [ nc ] [ ne ] [ net ] [ ng ] [ nl ] [ ns ] [ om ] [ pa ] [ pe ] [ ph ] [ query ] [ rc ] [ re ] [ release ] [ rl ] [ ru ] [ S ] [ SE ] [ se ] [ SED ] [ sh ] [ Sig ] [ spec ] [ st ] [ su ] [ T ] [ th ] [ to ] [ tr ] [ tt ] [ ug ] [ um ] [ us ] [ write ] [ write-only memory ]