Library /sys$common/syshlp/mime$help.hlb ADD, Example, Example  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    MIME> add myfile.txt

    This would add the file "myfile.txt" with the default settings
    specified by the program and also any found in the file
    MIME$FILETYPES.DAT file. The current default settings for a text
    (.TXT) file are: the content type set to "text/plain;" with a
    content type parameter of "charset=ISO-8859-1" and an encoding of
    "7bit/8bit". Use the SHOW FILE_TYPES command to display the list of
    file types and their settings.