+(defvar mm-file-name-rewrite-functions nil
+ "*List of functions used for rewriting file names of MIME parts.
+Each function takes a file name as input and returns a file name.
+
+Ready-made functions include
+`mm-file-name-delete-whitespace',
+`mm-file-name-trim-whitespace',
+`mm-file-name-collapse-whitespace',
+`mm-file-name-replace-whitespace',
+`capitalize', `downcase', `upcase', and
+`upcase-initials'.")
+
+(defvar mm-path-name-rewrite-functions nil
+ "*List of functions used for rewriting path names of MIME parts.
+This is used when viewing parts externally , and is meant for
+transforming the path name so that non-compliant programs can
+find the file where it's saved.
+
+Each function takes a file name as input and returns a file name.")
+
+(defvar mm-file-name-replace-whitespace nil
+ "String used for replacing whitespace characters; default is `\"_\"'.")
+
+(defcustom mm-default-directory nil
+ "The default directory where mm will save files.
+If not set, `default-directory' will be used."
+ :type '(choice directory (const :tag "Default" nil))
+ :group 'mime-display)
+
+(defcustom mm-external-terminal-program "xterm"
+ "The program to start an external terminal."
+ :type 'string
+ :group 'mime-display)
+