This chapter describes the C #define output module which can be selected with the @option{-Fcdef} option. @section Legal This module is written in 2020 by Volker Barthelmann and is covered by the vasm copyright without modifications. @section Additional options for this module There are currently no additional options for this output module. @section General This output module outputs the values of absolute symbols as a series of @code{#define} directives that can be included in a C compiler. No code is generated. @section Known Problems Some known problems of this module at the moment: @itemize @minus @item None. @end itemize @section Error Messages This module has no error messages: