qFilespec

                     filespec
──────────────────────────────────────────────────
Identifies a file.  It contains a 1-to-8-character
filename (with optional extension), optionally
preceded by a drive ID and directory path.

              fully-qualified filespec
          ┌─────────────┴─────────────────┐
 Example:  C:\WORDPROC\MYBOOK\CHAPTER1.TXT
          └┬┘└───────┬───────┘└─────┬─────┘
    drive ID     directory    filename.ext
──────────────────────────────────────────────────
■ All DOS API services will apply the current
  default drive and directory, if omitted.
■ DOS ignores character case in filespecs.
■ The d:\path string should not exceed 63 bytes.