The X
按字母分类：
extension name file type Classification
MAN Unix Manual text file
MBOX Email Mailbox File text file
MCW MacWrite II Document text file
MD5.TXT Message Digest 5 Hash File text file
ME Readme Text File text file
MELL Mellel Word Processing File text file
MELLEL Mellel Word Processing Document text file
MIN Mint Source File text file
MNT FoxPro Menu Memo text file
MSG Outlook Mail Message text file
MW MacWrite Text Document text file
MWD Mariner Write Document text file
MWP Lotus Word Pro SmartMaster File text file