dir *.txt *.doc        # filter by extension (both doc and txt)
dir    /a:-d            # files only (no subfolders)
dir /s                # current directory and subfolders content
dir /s /a:-d        # files only (including subfolders)
dir > myfile.txt    # stored in myfile.txt (dir /s > myfile.txt with subfolders)
dir /o:[sortorder]     # example:  dir /o:-s    (sort by decreasing size)
  N : By name (alphabetic).
  S : By size (smallest first).
  E : By extension (alphabetic).
  D : By date/time (oldest first).
  - : Prefix to reverse order.