+/* Attributes. */
+struct attrset *dict_get_attributes (const struct dictionary *);
+void dict_set_attributes (struct dictionary *, const struct attrset *);
+bool dict_has_attributes (const struct dictionary *);
+
+/* Data encoding. */
+void dict_set_encoding (struct dictionary *d, const char *enc);
+const char *dict_get_encoding (const struct dictionary *d);
+
+/* Internal variables. */
+struct variable *dict_create_internal_var (int case_idx, int width);
+void dict_destroy_internal_var (struct variable *);
+