No one else has mentioned _Include. This can contain a reference to your master .h file - it only has a bearing at the point in time that a developer creates a file (vcx, scx and maybe mnx and frx), not on existing files or Prg's (what a shame). Example :
_include = "d:\VFP8\ApplicationName\Include\Main.H"
This can also be set in Tools -> Options.
censored.