The /ALL flag on the DOS command line will force all objects to be
      rebuilt, regardless of their time and date stamps.

      It has the same effect as deleting all of your objects, without
      going through the actual process of deleting them. Instead, PBMake
      thinks that all of the time and date comparisons failed, ie:
      PBMake thinks that all of the source code is newer than all of the
      objects.

      MAKE MYPROG /ALL

      PBMake decides when the linker needs to run based on a few
      criteria.

      1. The output file is missing.
      2. The link script is newer than the output.
      3. An object was rebuilt. (like in the /ALL directive)
      4. An object was newer then the output.

      Use the /ALL command just before you are ready to distribute your
      application, to make sure that everything has been freshly
      compiled.

      Another time to use the /ALL command is when you are using the
      debugger. When you add the /B switch to the Clipper Compiler, you
      will want to rebuild all of the objects, so the debugging
      information is included in the objects. Then, when you are done
      debugging, you will remove the /B flag, and run /ALL again, to
      remove the extra debugging code and keep your executable faster
      and smaller.