This attribute is used in FILE or IDF elements to deal with binary data placed in the IDF document. This is a convenient means of including the content of binary files (i.e. non-text data such as images) "in-line" rather than as separate files.
If ENCODING is set, any body text found in the file will be converted from the base64 in which the binary was encoded and processed according to the FILETYPE.
If it is not set, the characters in the body text will used literally.