MIME Types settings

    MIME (Multipurpose Internet Mail Extensions) is an Internet standard for specifying what happens when a Web browser requests a file with certain characteristics.

    MIME allows Web servers and browsers to act appropriately when a file is requested. In the Mac OS, the action is based on a combination of the file's suffix, file type, and creator code. Each combination is called a "MIME type mapping."

Suffixes

    A suffix describes the type of data that's in a file. Suffixes begin with a period followed by letters. Here are some examples:
    • .txt for text files
    • .cgi for common gateway interface files
    • .gif for GIF (graphics) files
    • .au for sound files
    • .tiff for TIFF (graphics) files

Types

    The name of the MIME mapping includes two subfields separated by a slash (/) (for example, "text/plain"). To add or change a MIME type mapping, you may need to know the file type and creator code for a file. To get this information, you can use the program ResEdit, available from Apple Computer.

    To use ResEdit to find a file type and creator code:
    1 Locate the ResEdit icon on your computer, then drag the file to the ResEdit icon.
    2 When ResEdit opens, open the File menu and choose Get Info.
    The file type and creator code are displayed in the Type and Creator boxes.

Creator

    The creator is a 4-byte code indicating the application that created the file (for example, TTXT) or an asterisk (*) to indicate any creator.

Web Server Responses

    When a file is requested, the Web program handles the file using the MIME mapping that matches best:
    • A literal match takes precedence over a wild card (*) match.
    • The program uses the mapping that has the most matches with the file.
    • If two or more mappings have the same number of matches, the program uses the mapping that matches the file's suffix.

    Possible responses include:
    • Return file as MIME type
    • Encode file in MacBinary
    • Encode file in BinHex
    • Execute file as CGI
    • Handle file using plug-in <you specify plug-in name>
    • Execute file <you specify filename>

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