The following was cut from the Fetch help window and edited a bit ----

Automatic/Text/Binary

FTP (the protocol which Fetch uses to transfer files) divides files into two categories: text files and binary (or image) files. Furthermore, the Macintosh uses complex files that can only be represented on other computers with special formats. In order for a file transfer to work these issues must be worked out. Fetch has three buttons that control the way a file is retrieved: they are titled Automatic, Text, and Binary. It would be convenient if Fetch could always tell what sort of file it was getting and treat it in the appropriate way; unfortunately Fetch is not that clarivoyant. So some of the time you will have to specify what sort of file you are getting. The three possible settings are explained below.

Automatic Fetch starts out with the Automatic button selected, and this setting will be the right one most of the time. When this button is selected Fetch tries to interpret the name of the file you are getting. For instance, most BinHex files end in "hqx," and most GIF (Graphics Interchange Format) files end in "gif." When the Automatic button is selected these clues lead Fetch to download "hqx" files as text files (and ignore the non-BinHex part) and download "gif" files as binary files (with the right icon to be opened by a popular GIF viewing program). These clues are managed by the Suffix Mapping... menu command (see the "Suffix Mapping" help topic). Some file names will not offer any clues, and in that case Fetch will use its default behavior. The default behavior can be changed in Preferences. When Fetch believes a file is in BinHex format it discards all non-BinHex data and only allows you to save the converted file. This is a problem if you want the other data or if the file is only part, and not the first part, of a complete BinHex file (see Multi-Part BinHex Files). When Fetch thinks a file is text it prompts you for a name to give it and allows you to have it converted to filled paragraphs (see the "Filled Paragraphs" topic). The file will be of type TEXT and its file icon can be set in the Preferences dialog box. Fetch will detect the beginning of a BinHex file inside a text file and offer to convert the BinHex information; you have the option of declining this conversion by pressing the Don't Convert button. When Fetch thinks a file is binary information it first checks to see if it is in MacBinary II, AppleSingle, MacBinary I or MacHost format. If it is, it will be saved in its original state; otherwise you will be prompted to supply the type and creator of the file. A pop-up menu with a few popular types is available. The Automatic setting may do the wrong thing if the file name does not reveal the file type, or suggests the wrong file type (e.g. a ".txt" file that is in fact binary). For these situations you must use one of the other two settings.

Note: There are two notable exceptions to these rules for Automatic mode. If Fetch determines that the server machine is a Macintosh running the Macintosh Operating System (i.e. not A/UX or some other Unix) it will try to transfer all files in MacBinary mode. This way all files will appear exactly as they do on the server machine, except that StuffIt! archives may be expanded. Similarly, if Fetch determines that the server machine is a Macintosh running MachTen (a Unix variant) it will try to transfer all files in AppleSingle format, since AppleSingle is MachTen's preferred format for Macintosh files.

Text This setting tells Fetch that the file in question is a text file (or a BinHex file, which is one kind of text file). Since the Automatic setting usually treats mysterious files as text files this setting is rarely necessary. If, however, a text file has the sort of name usually associated with binary files (i.e. ending in "bin", "Z", "sit", "gif", or "tar") you should choose this setting to override the automatic behavior. Likewise if a filename ends in "hqx" but does not refer to a complete BinHex file or the first part of a complete BinHex file you should choose this setting.Some suffixes usually associated with binary files are hqx (BInHex), .

Binary This setting is for getting binary (i.e. non-text) files, specifically those files whose names do not identify them as being binary files. If you know that a file is not a text file (e.g. it is in MacBinary or AppleSingle format) choosing this setting will help ensure the proper treatment. When this button is set the file will be checked to see if it is in MacBinary, AppleSingle or MacHost format. If it is then it will be saved just in its original state; otherwise you will be prompted for the type and creator of the file. A pop-up menu with a few popular types is available; more can be added in the "Suffix Mapping" dialog.Some suffixes usually associated with binary files are "bin", "Z", "sit", "gif", or "tar".