With DECC$ARGV_PARSE_STYLE enabled, case is preserved in command-
    line arguments when the process has been set up for extended DCL
    parsing using SET PROCESS/PARSE_STYLE=EXTENDED.

    DECC$ARGV_PARSE_STYLE must be defined externally as a logical
    name or set in a function called using the LIB$INITIALIZE
    mechanism because it is evaluated before function main is
    called.