If OPERATION is `insert-file-contents', the argument corresponding to
TARGET may be a cons (FILENAME . BUFFER). In that case, FILENAME is a
-file name to look up, and BUFFER is a buffer that will contain the
-file (not yet decoded). If `file-coding-system-alist' specifies a
+file name to look up, and BUFFER is a buffer that contains the file's
+contents (not yet decoded). If `file-coding-system-alist' specifies a
function to call for FILENAME, that function should examine the
contents of BUFFER instead of reading the file.