An unused block of bits left in a binary so that it can later be modified by insertion of machine-language instructions there (typically, the patch space is modified to contain new code, and the superseded code is patched to contain a jump or call to the patch space). The widening use of HLLs has made this term rare it is now primarily historical outside IBM shops. See patch, zap, hook. [Jargon File]

In addition suitable contents:
[ = ] [ ad ] [ ag ] [ ai ] [ al ] [ am ] [ an ] [ ar ] [ arc ] [ arg ] [ as ] [ at ] [ B ] [ b ] [ be ] [ bi ] [ binary ] [ bit ] [ block ] [ by ] [ ca ] [ ch ] [ ck ] [ co ] [ code ] [ con ] [ de ] [ du ] [ ed ] [ ee ] [ er ] [ fi ] [ file ] [ ge ] [ gu ] [ h ] [ hat ] [ HLL ] [ hook ] [ hop ] [ hr ] [ IBM ] [ id ] [ ie ] [ il ] [ in ] [ io ] [ is ] [ it ] [ J ] [ Jargon File ] [ jump ] [ la ] [ language ] [ Lex ] [ LL ] [ ly ] [ M ] [ ma ] [ machine ] [ mo ] [ mod ] [ module ] [ mp ] [ na ] [ ne ] [ ng ] [ ni ] [ no ] [ ns ] [ nu ] [ op ] [ pa ] [ pe ] [ ph ] [ pr ] [ query ] [ rc ] [ re ] [ ru ] [ S ] [ se ] [ sh ] [ si ] [ so ] [ space ] [ st ] [ struct ] [ su ] [ T ] [ tc ] [ th ] [ to ] [ tr ] [ ua ] [ um ] [ up ] [ us ] [ za ] [ zap ]