The value of this variable is automatically appended to the end of program file names when those names do not contain explicit suffixes. A suffix is the portion of a file name that follows a period. For example, if CODE_SUFFIX were set to "COB", then CALL "PGMFILE" would look for a program called "PGMFILE.COB". If you do not set this variable, the runtime will try appending a suffix of ".acu" and then will try a blank suffix. The default value is empty.