Switch Directives

  - Local variables can appear anywhere in a program unit; they affect only
    part of the compilation.
  - Global variables must appear before the declaration part of the program
    or unit being compiled; they affect the entire compilation.

   Switch   Meaning
   $A       Align Data
   $B       Boolean Evaluation
   $D       Debug Information
   $E       Emulation
   $F       Force FAR Calls
   $G       Generate 286 Instructions
   $I       Input/Output Checking
   $K       Smart Callbacks
   $L       Local Symbol Information
   $N       Numeric Coprocessor
   $O       Overlay Code Generation
   $P       Open string parameters
   $Q       Overflow Checking
   $R       Range Checking
   $S       Stack-Overflow Checking
   $T       Type-Checked Pointers
   $V       Var-String Checking
   $W       Windows Stack Frame
   $X       Extended Syntax
   $Y       Symbol Reference Information

 {$F+,$R+,$E-,$D-}